Science.gov

Sample records for all-optical microwave signal

  1. All optical measurement of an unknown wideband microwave frequency

    NASA Astrophysics Data System (ADS)

    Kumar, A.; Priye, V.; Raj Singh, R.

    2016-12-01

    A novel all optical measurement scheme is proposed to measure wideband microwave frequencies up to 30 GHz. The proposed method is based on a four-wave mixing (FWM) approach in a semiconductor optical amplifier (SOA) of both even order side-bands generated by an unknown microwave frequency modulating an optical carrier. The optical power of a generated FWM signal depends on frequency spacing between extracted side-bands. A mathematical relation is established between FWM power and frequency of an unknown signal. A calibration curve is drawn based on the mathematical relation which predicts the unknown frequency from power withdrawn after FWM.

  2. All-optical signal processing at 10 GHz using a photonic crystal molecule

    SciTech Connect

    Combrié, Sylvain; Lehoucq, Gaëlle; Junay, Alexandra; De Rossi, Alfredo; Malaguti, Stefania; Bellanca, Gaetano; Trillo, Stefano; Ménager, Loic; Peter Reithmaier, Johann

    2013-11-04

    We report on 10 GHz operation of an all-optical gate based on an Indium Phosphide Photonic Crystal Molecule. Wavelength conversion and all-optical mixing of microwave signals are demonstrated using the 2 mW output of a mode locked diode laser. The spectral separation of the optical pump and signal is crucial in suppressing optical cross-talk.

  3. All-optical signal processing technique for secure optical communication

    NASA Astrophysics Data System (ADS)

    Qian, Feng-chen; Su, Bing; Ye, Ya-lin; Zhang, Qian; Lin, Shao-feng; Duan, Tao; Duan, Jie

    2015-10-01

    Secure optical communication technologies are important means to solve the physical layer security for optical network. We present a scheme of secure optical communication system by all-optical signal processing technique. The scheme consists of three parts, as all-optical signal processing unit, optical key sequence generator, and synchronous control unit. In the paper, all-optical signal processing method is key technology using all-optical exclusive disjunction (XOR) gate based on optical cross-gain modulation effect, has advantages of wide dynamic range of input optical signal, simple structure and so on. All-optical XOR gate composed of two semiconductor optical amplifiers (SOA) is a symmetrical structure. By controlling injection current, input signal power, delay and filter bandwidth, the extinction ratio of XOR can be greater than 8dB. Finally, some performance parameters are calculated and the results are analyzed. The simulation and experimental results show that the proposed method can be achieved over 10Gbps optical signal encryption and decryption, which is simple, easy to implement, and error-free diffusion.

  4. Nonlinear fiber applications for ultrafast all-optical signal processing

    NASA Astrophysics Data System (ADS)

    Kravtsov, Konstantin

    In the present dissertation different aspects of all-optical signal processing, enabled by the use of nonlinear fibers, are studied. In particular, we focus on applications of a novel heavily GeO2-doped (HD) nonlinear fiber, that appears to be superior to many other types of nonlinear fibers because of its high nonlinearity and suitability for the use in nonlinear optical loop mirrors (NOLMs). Different functions, such as all-optical switching, thresholding, and wavelength conversion, are demonstrated with the HD fibers in the NOLM configuration. These basic functions are later used for realization of ultrafast time-domain demultiplexers, clock recovery, detectors of short pulses in stealth communications, and primitive elements for analog computations. Another important technology that benefits from the use of nonlinear fiber-based signal processing is optical code-division multiple access (CDMA). It is shown in both theory and experiment that all-optical thresholding is a unique way of improving existing detection methods for optical CDMA. Also, it is the way of implementation of true asynchronous optical spread-spectrum networks, which allows full realization of optical CDMA potential. Some aspects of quantum signal processing and manipulation of quantum states are also studied in this work. It is shown that propagation and collisions of Thirring solitons lead to a substantial squeezing of quantum states, which may find applications for generation of squeezed light.

  5. Low power consumption and continuously tunable all-optical microwave filter based on an opto-mechanical microring resonator.

    PubMed

    Liu, Li; Yang, Yue; Li, Zhihua; Jin, Xing; Mo, Wenqin; Liu, Xing

    2017-01-23

    We propose and experimentally demonstrate a continuously tunable all-optical microwave filter using a silicon opto-mechanical microring resonator (MRR). By finely adjusting the pump light with submilliwatt power level, transmission spectrum of the MRR could be continuously shifted based on the nonlinear effects, including the opto-mechanical effect and thermo-optic effect. Therefore, in the case of optical single sideband (OSSB) modulation, the frequency intervals between the optical carrier (near one MRR resonance) and the corresponding resonance could be flexibly manipulated, which is the critical factor to achieve continuously tunable microwave photonic filter (MPF). In the experiment, the central frequency of the MPF could be continuously tuned from 6 GHz to 19 GHz with the pump power lower than -2.5 dBm. The proposed opto-mechanical device is competent to process microwave signals with dominant advantages, such as compact footprint, all-optical control and low power consumption. In the future, using light to control light, the opto-mechanical structure on silicon platforms might have many other potential applications in microwave systems, such as microwave switch.

  6. Investigation of group delay ripple distorted signals transmitted through all-optical 2R regenerators.

    PubMed

    Mok, Joe; Blows, Justin; Eggleton, Benjamin

    2004-09-20

    We investigate the use of all-optical regenerators to correct pulse distortions introduced by group delay ripple. Group delay ripple creates unwanted satellite pulses and intensity fluctuations. By placing an all-optical regenerator after a device that introduces group delay ripple, we show that the signal distortions can be effectively reduced. This has the benefit of opening the signal eye at the receiver. The performances of both self-phase modulation and four-wave mixing based regenerators in reducing ripple induced system penalties are examined. We find that the regenerator based on four-wave mixing achieves better suppression of group delay ripple distortions than the self-phase modulation based alternative. The eye closure penalty introduced by group delay ripple is reduced by the four-wave mixing based regenerator by 1dB.

  7. Signal-quality consideration for dynamic connection provisioning in all-optical wavelength-routed networks

    NASA Astrophysics Data System (ADS)

    Huang, Yurong R.; Wen, Wushao; Heritage, Jonathan P.; Mukherjee, Biswanath

    2003-10-01

    We investigate new connection-provisioning algorithms to efficiently provide signal-quality-guaranteed connections in an all-optical WDM mesh network. In the all-optical network, signal degradations incurred by non-ideal transmission medium accumulate along a lightpath. When the signal degradation reaches a certain level, the connection is not usable and is blocked due to transmission impairments in the physical layer. To ensure high service quality of provisioned connections, it is essential to develop intelligent routing and wavelength assignment (RWA) algorithms which can combat the effects of impairments when setting up a connection. For this purpose, we propose two impairment-aware RWA algorithms, namely impairment-aware best-path (IABP) algorithm and impairment-aware first-fit (IAFF) algorithm. The optical signal-to-noise raito (OSNR) requirement and polarization mode dispersion (PMD) effect are used as signal-quality constraints to avoid setting up a connection with unacceptable quality due to the effects of transmission impairments. With the signal-quality consideration, as compared to algorithms that are not impairment aware in a realistic optical network, our proposed impairment-aware algorithms efficiently provide signal-quality-guaranteed connection while significantly reducing connection-blocking probability, better utilizing network resources, and having a reasonable computational requirement. Also, the effect of channel bit rate is studied in this paper.

  8. High Speed All Optical Nyquist Signal Generation and Full-band Coherent Detection

    PubMed Central

    Zhang, Junwen; Yu, Jianjun; Fang, Yuan; Chi, Nan

    2014-01-01

    Spectrum efficient data transmission is of key interest for high capacity optical communication systems considering the limited available bandwidth. Transmission of the high speed signal with higher-order modulation formats within the Nyquist bandwidth using coherent detection brings attractive performance advantages. However, high speed Nyquist signal generation with high order modulation formats is challenging. Electrical Nyquist pulse generation is restricted by the limited sampling rate and processor capacities of digital-to-analog convertor devices, while the optical Nyquist signals can provide a much higher symbol rate using time domain multiplexing method. However, most optical Nyquist signals are based on direct detection with simple modulation formats. Here we report the first experimental demonstration of high speed all optical Nyquist signal generation based on Sinc-shaped pulse generation and time-division multiplexing with high level modulation format and full-band coherent detection. Our experiments demonstrate a highly flexible and compatible all optical high speed Nyquist signal generation and detection scheme for future fiber communication systems. PMID:25142269

  9. All-optical non-conjugated wavelength multicasting of QPSK signal with capability of phase regeneration.

    PubMed

    Lian, Junzi; Fu, Songnian; Meng, Yan; Tang, Ming; Shum, Perry; Liu, Deming

    2014-09-22

    We propose all-optical one-to-three non-conjugated wavelength multicasting of QPSK signal with capability of phase regeneration, using dual-conjugated-pump phase sensitive amplification (PSA). Based on the seven-wave model, we can obtain phase transfer functions of individual multicasting channel. Different from two multicasting copies, the phase regeneration performance of input signal is determined by the nonlinear phase shift. Moreover, the optimal squeezing points of three multicasting channels have a deviation. Thus, there exists a regeneration performance trade-off among three multicasting channels. Our numerical simulation shows that the error vector magnitude (EVM) of 50 Gb/s QPSK signal can be successfully improved when both nonlinear phase shift and four-state position in its constellation are optimized. The calculated BER curves verify that the OSNR penalties of three multicasting channels are improved by around 1dB at BER = 10(-3).

  10. Gold nanoparticle-assisted all optical localized stimulation and monitoring of Ca2+ signaling in neurons

    PubMed Central

    Lavoie-Cardinal, Flavie; Salesse, Charleen; Bergeron, Éric; Meunier, Michel; De Koninck, Paul

    2016-01-01

    Light-assisted manipulation of cells to control membrane activity or intracellular signaling has become a major avenue in life sciences. However, the ability to perform subcellular light stimulation to investigate localized signaling has been limited. Here, we introduce an all optical method for the stimulation and the monitoring of localized Ca2+ signaling in neurons that takes advantage of plasmonic excitation of gold nanoparticles (AuNPs). We show with confocal microscopy that 800 nm laser pulse application onto a neuron decorated with a few AuNPs triggers a transient increase in free Ca2+, measured optically with GCaMP6s. We show that action potentials, measured electrophysiologically, can be induced with this approach. We demonstrate activation of local Ca2+ transients and Ca2+ signaling via CaMKII in dendritic domains, by illuminating a single or few functionalized AuNPs specifically targeting genetically-modified neurons. This NP-Assisted Localized Optical Stimulation (NALOS) provides a new complement to light-dependent methods for controlling neuronal activity and cell signaling. PMID:26857748

  11. High-speed and reconfigurable all-optical signal processing for phase and amplitude modulated signals

    NASA Astrophysics Data System (ADS)

    Khaleghi, Salman

    Technology has empowered people in all walks of life to generate, store, and communicate enormous amounts of data. Recent technological advances in high-speed backbone data networks, together with the growing trend toward bandwidth-demanding applications such as data and video sharing, cloud computing, and data collection systems, have created a need for higher capacities in signal transmission and signal processing. Optical communication systems have long benefited from the large bandwidth of optical signals (beyond tera-hertz) to transmit information. Through the use of optical signal processing techniques, this Ph.D. dissertation explores the potential of very-high-speed optics to assist electronics in processing huge amounts of data at high speeds. Optical signal processing brings together various fields of optics and signal processing---nonlinear devices and processes, analog and digital signals, and advanced data modulation formats---to achieve high-speed signal processing functions that can potentially operate at the line rate of fiber optic communications. Information can be encoded in amplitude, phase, wavelength, polarization, and spatial features of an optical wave to achieve high-capacity transmission. Many advances in the key enabling technologies have led to recent research in optical signal processing for digital signals that are encoded in one or more of these dimensions. Optical Kerr nonlinearities have femto-second response times that have been exploited for fast processing of optical signals. Various optical nonlinearities and chromatic dispersions have enabled key sub-system applications such as wavelength conversion, multicasting, multiplexing, demultiplexing, and tunable optical delays. In this Ph.D. dissertation, we employ these recent advances in the enabling technologies for high-speed optical signal processing to demonstrate various techniques that can process phase- and amplitude-encoded optical signals at the line rate of optics. We use

  12. All-optical, ultra-wideband microwave I/Q mixer and image-reject frequency down-converter.

    PubMed

    Gao, Yongsheng; Wen, Aijun; Chen, Wei; Li, Xiaoyan

    2017-03-15

    An all-optical and ultra-wideband microwave in-phase/quadrature (I/Q) mixer, based on a dual-parallel Mach-Zehnder modulator and a wavelength division multiplexer, is proposed. Due to the simultaneous frequency down-conversion and 360-deg tunable phase shifting in the optical domain, the proposed I/Q mixer has the advantages of high conversion gain and excellent quadrature phase balance (<±1.3 deg⁡) with a wide operating frequency from 10 to 40 GHz. Assisted by an analog or digital intermediate-frequency quadrature coupler, an image-reject frequency down-converter is then implemented, with an image rejection exceeding 50 dB over the working band.

  13. Applications of all optical signal processing for advanced optical modulation formats

    NASA Astrophysics Data System (ADS)

    Nuccio, Scott R.

    signal processing may play a role in the future development of more efficient optical transmission systems. The hope is that performing signal processing in the optical domain may reduce optical-to-electronic conversion inefficiencies, eliminate bottlenecks and take advantage of the ultrahigh bandwidth inherent in optics. While 40 to 50 Gbit/s electronic components are the peak of commercial technology and 100 Gbit/s capable RF components are still in their infancy, optical signal processing of these high-speed data signals may provide a potential solution. Furthermore, any optical processing system or sub-system must be capable of handling the wide array of data formats and data rates that networks may employ. It is also worth noting that future networks may use a combination of data-rates and formats while it has been estimated that "we may start seeing the first commercial use of Terabit Ethernets by 2015". -Robert Metcalfe. To this end, the work presented in this Ph.D. dissertation is aimed at addressing the issue of optical processing for advanced optical modulation formats. All optical multiplexing and demultiplexing of Pol-MUX and phase and QAM encoded signals at the 100 Gbit/s Ethernet standard is addressed. The creation and development of an extremely large continuously tunable all-optical delay capable of handling a variety of modulation formats and data rates is presented. As optical delays are viewed as a critical element to achieve efficient and reconfigurable signal processing, the presented delay line is also utilized to enable a tunable packet buffer capable of handling data packets of varying rate, varying size, and multiple modulation formats.

  14. All-optical multi-channel wavelength conversion of Nyquist 16 QAM signal using a silicon waveguide.

    PubMed

    Long, Yun; Liu, Jun; Hu, Xiao; Wang, Andong; Zhou, Linjie; Zou, Kaiheng; Zhu, Yixiao; Zhang, Fan; Wang, Jian

    2015-12-01

    We experimentally demonstrate on-chip all-optical multi-channel wavelength conversion of Nyquist 16 ary quadrature amplitude modulation (16 QAM) signal in a silicon waveguide. The measured optical signal-to-noise ratio (OSNR) penalties of wavelength conversion are ∼2  dB. The observed constellations of converted idlers indicate favorable performance of silicon-waveguide-based multi-channel wavelength conversion. We also experimentally study and compare the phase-conjugated wavelength conversion by degenerate four-wave mixing (FWM) and transparent wavelength conversion by non-degenerate FWM in the silicon waveguide.

  15. Harnessing mode-selective nonlinear optics for on-chip multi-channel all-optical signal processing

    NASA Astrophysics Data System (ADS)

    Ma, Ming; Chen, Lawrence R.

    2016-11-01

    All-optical signal processing based on nonlinear optical effects allows for the realization of important functions in telecommunications including wavelength conversion, optical multiplexing/demultiplexing, Fourier transformation, and regeneration, amongst others, on ultrafast time scales to support high data rate transmission. In integrated photonic subsystems, the majority of all-optical signal processing systems demonstrated to date typically process only a single channel at a time or perform a single processing function, which imposes a serious limitation on the functionality of integrated solutions. Here, we demonstrate how nonlinear optical effects can be harnessed in a mode-selective manner to perform simultaneous multi-channel (two) and multi-functional optical signal processing (i.e., regenerative wavelength conversion) in an integrated silicon photonic device. This approach, which can be scaled to a higher number of channels, opens up a new degree of freedom for performing a broad range of multi-channel nonlinear optical signal processing functions using a single integrated photonic device.

  16. Simple all-optical FFT scheme enabling Tbit/s real-time signal processing.

    PubMed

    Hillerkuss, D; Winter, M; Teschke, M; Marculescu, A; Li, J; Sigurdsson, G; Worms, K; Ben Ezra, S; Narkiss, N; Freude, W; Leuthold, J

    2010-04-26

    A practical scheme to perform the fast Fourier transform in the optical domain is introduced. Optical real-time FFT signal processing is performed at speeds far beyond the limits of electronic digital processing, and with negligible energy consumption. To illustrate the power of the method we demonstrate an optical 400 Gbit/s OFDM receiver. It performs an optical real-time FFT on the consolidated OFDM data stream, thereby demultiplexing the signal into lower bit rate subcarrier tributaries, which can then be processed electronically.

  17. Cascadability properties of MZI-SOA-based all-optical 3R regenerators for RZ-DPSK signals.

    PubMed

    Kise, Tomofumi; Nguyen, Kimchau N; Garcia, John M; Poulsen, Henrik N; Blumenthal, Daniel J

    2011-05-09

    We experimentally demonstrate 50 cascaded all-optical 3R regenerators over a 1,000 km transmission distance for 10-Gb/s return-to-zero differential phase-shift keying (RZ-DPSK) signals. The regenerator consists of integrated Mach-Zehnder interferometer (MZI) semiconductor optical amplifier (SOA) based wavelength converters. Regenerative properties and tolerance to pattern dependent effects have been studied in terms of Q-factor measurement, and error free operation with input OSNR of 20 dB/0.1 nm has also been demonstrated.

  18. Ultrafast all-optical switching using signal flow graph for PANDA resonator.

    PubMed

    Bahadoran, Mahdi; Ali, Jalil; Yupapin, Preecha P

    2013-04-20

    In this paper, the bifurcation behavior of light in the PANDA ring resonator is investigated using the signal flow graph (SFG) method, where the optical transfer function for the through and drop ports of the PANDA Vernier system are derived. The optical nonlinear phenomena, such as bistability, Ikeda instability, and dynamics of light in the silicon-on-insulator (SOI) PANDA ring resonator with four couplers are studied. The transmission curves for bistability and instability as a function of the resonant mode numbers and coupling coefficients for the coupler are derived by the SFG method and simulated. The proposed system has an advantage as no optical pumping component is required. Simulated results show that closed-loop bistable switching can be generated and achieved by varying mode resonant numbers in the SOI-PANDA Vernier resonator, where a smooth and closed-loop bistable switching with low relative output/input power can be obtained and realized. The minimum through-port switching time of 1.1 ps for resonant mode numbers of 5;4;4 and minimum drop port switching time of 1.96 ps for resonant mode numbers of 9;7;7 of the PANDA Vernier resonator are achieved, which makes the PANDA Vernier resonator an operative component for optical applications, such as optical signal processing and a fast switching key in photonics integrated circuits.

  19. Gigahertz to terahertz tunable all-optical single-side-band microwave generation via semiconductor optical amplifier gain engineering.

    PubMed

    Li, Fangxin; Helmy, Amr S

    2013-11-15

    We propose and demonstrate a technique to generate low-noise broadly tunable single-side-band microwaves using cascaded semiconductor optical amplifiers (SOAs) using no RF bias. The proposed technique uses no RF components and is based on polarization-state controlled gain-induced four-wave mixing in SOAs. Microwave generation from 40 to 875 GHz with a line-width ~22 KHz is experimentally demonstrated.

  20. Numerical simulation of all-optical wavelength conversion of DPSK signal based on SOA in a Mach-Zehnder configuration

    NASA Astrophysics Data System (ADS)

    Hong, Wei; Li, Minghao; Huang, Dexiu; Zhang, Xinliang; Zhu, Guangxi

    2008-11-01

    All-optical wavelength conversion of differential phase-shift keyed (DPSK) signals based on SOA in a Mach-Zehnder interferometer (SOA-MZI) configuration is simulated and analyzed using the transfer function of MZI and a wideband dynamic model of SOA. The operation principle is analyzed and operation point selection, influence of SOA physical parameters, different signal format and operation speed are discussed in detail. The results of 10Gb/s operation show that SOA-MZI is compatible with both non-return-to-zero (NRZ) and return-to-zero (RZ) formatted signals. However, the conversion performance is sensitive to the operation point of the involved SOAs. To maximize the Q value of the demodulated conversion signal, the power and wavelength of the original DPSK signal and the probe light should be optimized to obtain approximately π phase difference between the upper and lower arms of MZI in the middle of each bit. Besides, SOA with short carrier lifetime and large linewidth enhancement factor is preferred for wavelength conversion applications. 40Gb/s operation is also simulated with SOA carrier lifetime of 100ps, and the results strongly suggests 40Gb/s operation with RZ formatted signals and relatively large input powers of the clock signal.

  1. All optical up-converted signal generation with high dispersion tolerance using frequency quadrupling technique for radio over fiber system

    NASA Astrophysics Data System (ADS)

    Gu, Yiying; Zhao, Jiayi; Hu, Jingjing; Kang, Zijian; Zhu, Wenwu; Fan, Feng; Han, Xiuyou; Zhao, Mingshan

    2016-05-01

    A novel all optical up-converted signal generation scheme with optical single-sideband (OSSB) technique for radio over fiber (RoF) application is presented and experimentally demonstrated using low-bandwidth devices. The OSSB signal is generated by one low-bandwidth intensity LiNbO3 Mach-Zehnder modulator (LN-MZM) under frequency quadrupling modulation scheme and one low-bandwidth LN-MZM under double sideband carrier suppressed modulation (DSB-CS) scheme. The proposed all OSSB generation scheme is capable of high tolerance of fiber chromatic dispersion induced power fading (DIPF) effect. Benefiting from this novel OSSB generation scheme, a 26 GHz radio frequency (RF) signal up-conversion is realized successfully when one sideband of the optical LO signal is reused as the optical carrier for intermediate frequency (IF) signal modulation. The received vector signal transmission over long distance single-mode fiber (SMF) shows negligible DIPF effect with the error vector magnitude (EVM) of 15.7% rms. In addition, a spurious free dynamic range (SFDR) of the OSSB up-converting system is measured up to 81 dB Hz2/3. The experiment results indicate that the proposed system may find potential applications in future wireless communication networks, especially in microcellular personal communication system (MPCS).

  2. Transmission and full-band coherent detection of polarization-multiplexed all-optical Nyquist signals generated by Sinc-shaped Nyquist pulses.

    PubMed

    Zhang, Junwen; Yu, Jianjun; Chi, Nan

    2015-09-01

    All optical method is considered as a promising technique for high symbol rate Nyquist signal generation, which has attracted a lot of research interests for high spectral-efficiency and high-capacity optical communication system. In this paper, we extend our previous work and report the fully experimental demonstration of polarization-division multiplexed (PDM) all-optical Nyquist signal generation based on Sinc-shaped Nyquist pulse with advanced modulation formats, fiber-transmission and single-receiver full-band coherent detection. Using this scheme, we have successfully demonstrated the generation, fiber transmission and single-receiver full-band coherent detection of all-optical Nyquist PDM-QPSK and PDM-16QAM signals up to 125-GBaud. 1-Tb/s single-carrier PDM-16QAM signal generation and full-band coherent detection is realized, which shows the advantage and feasibility of the single-carrier all-optical Nyquist signals.

  3. Transmission and full-band coherent detection of polarization-multiplexed all-optical Nyquist signals generated by Sinc-shaped Nyquist pulses

    PubMed Central

    Zhang, Junwen; Yu, Jianjun; Chi, Nan

    2015-01-01

    All optical method is considered as a promising technique for high symbol rate Nyquist signal generation, which has attracted a lot of research interests for high spectral-efficiency and high-capacity optical communication system. In this paper, we extend our previous work and report the fully experimental demonstration of polarization-division multiplexed (PDM) all-optical Nyquist signal generation based on Sinc-shaped Nyquist pulse with advanced modulation formats, fiber-transmission and single-receiver full-band coherent detection. Using this scheme, we have successfully demonstrated the generation, fiber transmission and single-receiver full-band coherent detection of all-optical Nyquist PDM-QPSK and PDM-16QAM signals up to 125-GBaud. 1-Tb/s single-carrier PDM-16QAM signal generation and full-band coherent detection is realized, which shows the advantage and feasibility of the single-carrier all-optical Nyquist signals. PMID:26323238

  4. Transmission and full-band coherent detection of polarization-multiplexed all-optical Nyquist signals generated by Sinc-shaped Nyquist pulses

    NASA Astrophysics Data System (ADS)

    Zhang, Junwen; Yu, Jianjun; Chi, Nan

    2015-09-01

    All optical method is considered as a promising technique for high symbol rate Nyquist signal generation, which has attracted a lot of research interests for high spectral-efficiency and high-capacity optical communication system. In this paper, we extend our previous work and report the fully experimental demonstration of polarization-division multiplexed (PDM) all-optical Nyquist signal generation based on Sinc-shaped Nyquist pulse with advanced modulation formats, fiber-transmission and single-receiver full-band coherent detection. Using this scheme, we have successfully demonstrated the generation, fiber transmission and single-receiver full-band coherent detection of all-optical Nyquist PDM-QPSK and PDM-16QAM signals up to 125-GBaud. 1-Tb/s single-carrier PDM-16QAM signal generation and full-band coherent detection is realized, which shows the advantage and feasibility of the single-carrier all-optical Nyquist signals.

  5. Transmission and pass-drop operations of mixed baudrate Nyquist OTDM-WDM signals for all-optical elastic network.

    PubMed

    Tan, Hung Nguyen; Inoue, Takashi; Kurosu, Takayuki; Namiki, Shu

    2013-08-26

    We propose the use of Nyquist OTDM-WDM signal for highly efficient, fully elastic all-optical networks. With the possibility of generation of ultra-coarse yet flexible granular channels, Nyquist OTDM-WDM can eliminate guard-bands in conventional WDM systems, and hence improves the spectral efficiency in network perspective. In this paper, transmission and pass-drop operations of mixed baudrate Nyquist OTDM-WDM channels from 43 Gbaud to dual-polarization 344 Gbaud are successfully demonstrated over 320 km fiber link with four FlexGrid-compatible WSS nodes. A stable clock recovery is also carried out for different baudrate Nyquist OTDMs by optical null-header insertion technique.

  6. Generation of 21.3 Gbaud 8PSK signal using an SOA-based all-optical phase modulator.

    PubMed

    Dailey, J M; Webb, R P; Manning, R J

    2011-12-12

    We describe a novel SOA-based all-optical pure-phase modulator, and show how deleterious cross-gain modulation from the SOAs can be suppressed by utilizing an integrated interferometer structure. We experimentally demonstrate the use of the optical gate as a π/4 phase modulator producing 21.3 Gbaud 8PSK from 21.3 Gbit/s OOK and 21.3 Gbaud QPSK inputs. The modulator produces 3 dB of gain and coherent detection-based bit error rate measurements indicate a 2.4 dB excess penalty.

  7. All-optical analog comparator.

    PubMed

    Li, Pu; Yi, Xiaogang; Liu, Xianglian; Zhao, Dongliang; Zhao, Yongpeng; Wang, Yuncai

    2016-08-23

    An analog comparator is one of the core units in all-optical analog-to-digital conversion (AO-ADC) systems, which digitizes different amplitude levels into two levels of logical '1' or '0' by comparing with a defined decision threshold. Although various outstanding photonic ADC approaches have been reported, almost all of them necessitate an electrical comparator to carry out this binarization. The use of an electrical comparator is in contradiction to the aim of developing all-optical devices. In this work, we propose a new concept of an all-optical analog comparator and numerically demonstrate an implementation based on a quarter-wavelength-shifted distributed feedback laser diode (QWS DFB-LD) with multiple quantum well (MQW) structures. Our results show that the all-optical comparator is very well suited for true AO-ADCs, enabling the whole digital conversion from an analog optical signal (continuous-time signal or discrete pulse signal) to a binary representation totally in the optical domain. In particular, this all-optical analog comparator possesses a low threshold power (several mW), high extinction ratio (up to 40 dB), fast operation rate (of the order of tens of Gb/s) and a step-like transfer function.

  8. All-optical analog comparator

    NASA Astrophysics Data System (ADS)

    Li, Pu; Yi, Xiaogang; Liu, Xianglian; Zhao, Dongliang; Zhao, Yongpeng; Wang, Yuncai

    2016-08-01

    An analog comparator is one of the core units in all-optical analog-to-digital conversion (AO-ADC) systems, which digitizes different amplitude levels into two levels of logical ‘1’ or ‘0’ by comparing with a defined decision threshold. Although various outstanding photonic ADC approaches have been reported, almost all of them necessitate an electrical comparator to carry out this binarization. The use of an electrical comparator is in contradiction to the aim of developing all-optical devices. In this work, we propose a new concept of an all-optical analog comparator and numerically demonstrate an implementation based on a quarter-wavelength-shifted distributed feedback laser diode (QWS DFB-LD) with multiple quantum well (MQW) structures. Our results show that the all-optical comparator is very well suited for true AO-ADCs, enabling the whole digital conversion from an analog optical signal (continuous-time signal or discrete pulse signal) to a binary representation totally in the optical domain. In particular, this all-optical analog comparator possesses a low threshold power (several mW), high extinction ratio (up to 40 dB), fast operation rate (of the order of tens of Gb/s) and a step-like transfer function.

  9. All-optical analog comparator

    PubMed Central

    Li, Pu; Yi, Xiaogang; Liu, Xianglian; Zhao, Dongliang; Zhao, Yongpeng; Wang, Yuncai

    2016-01-01

    An analog comparator is one of the core units in all-optical analog-to-digital conversion (AO-ADC) systems, which digitizes different amplitude levels into two levels of logical ‘1’ or ‘0’ by comparing with a defined decision threshold. Although various outstanding photonic ADC approaches have been reported, almost all of them necessitate an electrical comparator to carry out this binarization. The use of an electrical comparator is in contradiction to the aim of developing all-optical devices. In this work, we propose a new concept of an all-optical analog comparator and numerically demonstrate an implementation based on a quarter-wavelength-shifted distributed feedback laser diode (QWS DFB-LD) with multiple quantum well (MQW) structures. Our results show that the all-optical comparator is very well suited for true AO-ADCs, enabling the whole digital conversion from an analog optical signal (continuous-time signal or discrete pulse signal) to a binary representation totally in the optical domain. In particular, this all-optical analog comparator possesses a low threshold power (several mW), high extinction ratio (up to 40 dB), fast operation rate (of the order of tens of Gb/s) and a step-like transfer function. PMID:27550874

  10. Simultaneous all-optical phase noise mitigation and automatically locked homodyne reception of an incoming QPSK data signal.

    PubMed

    Mohajerin-Ariaei, Amirhossein; Ziyadi, Morteza; Almaiman, Ahmed; Cao, Yinwen; Alishahi, Fatemeh; Chitgarha, Mohammad Reza; Fallahpour, Ahmad; Yang, Jeng-Yuan; Bao, Changjing; Liao, Peicheng; Shamee, Bishara; Akasaka, Youichi; Sekiya, Motoyoshi; Touch, Joseph D; Tur, Moshe; Langrock, Carsten; Fejer, Martin M; Willner, Alan E

    2016-10-15

    Simultaneous phase noise mitigation and automatic phase/frequency-locked homodyne reception is demonstrated for a 20-32 Gbaud QPSK signal. A phase quantization function is realized to squeeze the phase noise of the signal by optical wave mixing of the signal, its third-order harmonic, and their corresponding delayed variant conjugates, converting the noisy input into a noise-mitigated signal. In a simultaneous nonlinear process, the noise-mitigated signal is automatically phase- and frequency-locked with a "local" pump laser, avoiding the need for feedback or phase/frequency tracking for homodyne detection. Open eye-diagrams are obtained for in-phase and quadrature-phase components of the signal and ∼2  dB OSNR gain is achieved at BER 10-3.

  11. On-chip all-optical wavelength conversion of multicarrier, multilevel modulation (OFDM m-QAM) signals using a silicon waveguide.

    PubMed

    Li, Chao; Gui, Chengcheng; Xiao, Xi; Yang, Qi; Yu, Shaohua; Wang, Jian

    2014-08-01

    We report on-chip all-optical wavelength conversion of multicarrier multilevel modulation signals in a silicon waveguide. Using orthogonal frequency-division multiplexing (OFDM) combined with advanced multilevel quadrature amplitude modulation (QAM) signals (i.e., OFDM m-QAM), we experimentally demonstrate all-optical wavelength conversions of 3.2 Gbaud/s OFDM 16/32/64/128-QAM signals based on the degenerate four-wave mixing (FWM) nonlinear effect in a silicon waveguide. The measured optical signal-to-noise ratio (OSNR) penalties of wavelength conversion are ∼3  dB for OFDM 16-QAM and ∼4  dB for OFDM 32-QAM at 7% forward error correction (FEC) threshold and ∼3.5  dB for OFDM 64-QAM and ∼4.5  dB for OFDM 128-QAM at 20% FEC threshold. The observed clear constellations of converted idlers imply favorable performance obtained for silicon-waveguide-based OFDM 16/32/64/128-QAM wavelength conversions.

  12. Chromatic dispersion induced PM-AM conversion and its application in the all-optical clock recovery of NRZ-DPSK signals

    NASA Astrophysics Data System (ADS)

    Tang, Ming; Fu, Songnian; Zhong, Wen-de; Wen, Yang Jing; Shum, Ping

    2007-11-01

    We investigated the property of conversion between phase modulation (PM) and amplitude modulation (AM) in optical fiber transmission link due to chromatic dispersion (CD) for the purpose of clock information generation. As a result, a novel all-optical clock recovery (CR) scheme from 10 Gbps non-return-to-zero differential phase-shift-keying (NRZ-DPSK) signal has been demonstrated experimentally. We introduce a chromatic dispersion induced clock tone from the NRZ-DPSK signal and feed it into a free-running semiconductor optical amplifier (SOA) based fiber ring laser to achieve an injection mode-locking. The generated mode-locked pulse is the corresponding regenerated clock of the original signal. Since no special component is required for NRZ-DPSK demodulation, our proposed method is very promising because of its simple configuration and higher stability. In experiments, 20km standard single mode fiber is employed to accumulate CD and generate PM-AM conversion hence regenerate clock tone of the NRZ-DPSK signal. The recovered clock signal with the extinction ratio over 15 dB and the root-mean-square timing jitter of 720 fs is achieved under 2 31-1 pseudorandom binary sequence NRZ-DPSK signals measurement. We also demonstrated a similar CR system by using a chirped fiber Bragg grating (CFBG) as the dispersion device. With the same operation principle, it is quite convenient and promising to extend our configuration to implement all-optical CR for NRZ-DPSK signal with data rate up to 40Gbps.

  13. All-optical demultiplexing of 16-QAM signals into QPSK tributaries using four-level optical phase quantizers.

    PubMed

    Bogris, Adonis

    2014-04-01

    The potential of four-level optical phase quantizers toward coherent processing of advanced modulation formats, such as 16-QAM, is proposed and numerically demonstrated. The work shows that phase quantization achieved in fiber-based phase-sensitive amplifiers can demultiplex 16-QAM into two quadrature phase shift keying (QPSK) signals, enabling subchannel switching. The numerical study highlights the impact of the quantizer transfer function on the performance of the demultiplexing process and numerically calculates the bit error rate for each QPSK tributary after the demultiplexing procedure.

  14. Graphene-silicon microring resonator enhanced all-optical up and down wavelength conversion of QPSK signal.

    PubMed

    Hu, Xiao; Long, Yun; Ji, Mengxi; Wang, Andong; Zhu, Long; Ruan, Zhengsen; Wang, Yi; Wang, Jian

    2016-04-04

    We fabricate a nonlinear optical device based on graphene-silicon microring resonator (GSMR). Using such graphene-assisted nonlinear optical device, we experimentally demonstrate up and down wavelength conversion of a 10-Gbaud quadrature phase-shift keying (QPSK) signal by exploiting degenerate four-wave mixing (FWM) progress in the fabricated GSMR. We study the conversion efficiency as a function of the pump power. In addition, the resonant wavelength of GSMR is tuned by changing the temperature from 20°C to 40°C. We evaluate the bit-error rate (BER) performance for up and down wavelength conversion. The observed optical signal-to-noise ratio (OSNR) penalties for QPSK up and down wavelength conversion are less than 1.4 dB at a BER of 1 × 10-3. The BER performance as a function of the pump power for up wavelength conversion is also assessed. The minimum OSNR penalty is less than 0.8 dB when the pump power is 13.3 dBm.

  15. Experimental characterization of an all-optical wavelength converter of OFDM signals using two-mode injection-locking in a Fabry-Pérot laser.

    PubMed

    Dang, Juntao; Yi, Xingwen; Zhang, Jing; Ye, Taiping; Xu, Bo; Qiu, Kun

    2016-07-25

    While optical OFDM has been demonstrated for superior transmission performance, its analogue waveform in the time domain challenges many conventional all-optical wavelength converters (AOWC) that are needed for future flexible optical networks. There only exist a few reports on AOWC of OFDM signals, which are mainly based on the low-efficient four-wave mixing. In this paper, we propose an AOWC for OFDM signals by using two-mode injection-locking in a low-cost Fabry-Pérot laser. The control signal and the probe signal at a milliwatt power level are combined and injected into the FP laser. By a proper control, they can be injection-locked to two longitudinal modes in the FP laser and subsequently, the transmission of the probe signal is conditioned by the control signal. We conduct an experimental study on various aspects of this AOWC. Despite a vendor-specified electrical-to-optical (E/O) modulation bandwidth of 2.5 GHz, we find that the optical-to-optical (O/O) modulation bandwidth of AOWC is free from this limit and can be much wider. We examine the linear transfer curve of the AOWC by simply using the OFDM waveforms as the stimulus. The performance tolerance to the wavelength detuning and injected power ratio is also measured. The proposed AOWC can provide a linear transfer function from the control signal to the probe signal to support the random-fluctuated OFDM waveform. We also investigate the maximum capacity of the AOWC by using the adaptive bit-loading OFDM. Finally, we measure the power penalty after the AOWC at two different bit rates to show the tradeoff between the penalty and capacity.

  16. Digital signal processing in microwave radiometers

    NASA Technical Reports Server (NTRS)

    Lawrence, R. W.; Stanley, W. D.; Harrington, R. F.

    1980-01-01

    A microprocessor based digital signal processing unit has been proposed to replace analog sections of a microwave radiometer. A brief introduction to the radiometer system involved and a description of problems encountered in the use of digital techniques in radiometer design are discussed. An analysis of the digital signal processor as part of the radiometer is then presented.

  17. Microwave signal processing with photorefractive dynamic holography

    NASA Astrophysics Data System (ADS)

    Fotheringham, Edeline B.

    Have you ever found yourself listening to the music playing from the closest stereo rather than to the bromidic (uninspiring) person speaking to you? Your ears receive information from two sources but your brain listens to only one. What if your cell phone could distinguish among signals sharing the same bandwidth too? There would be no "full" channels to stop you from placing or receiving a call. This thesis presents a nonlinear optical circuit capable of distinguishing uncorrelated signals that have overlapping temporal bandwidths. This so called autotuning filter is the size of a U.S. quarter dollar and requires less than 3 mW of optical power to operate. It is basically an oscillator in which the losses are compensated with dynamic holographic gain. The combination of two photorefractive crystals in the resonator governs the filter's winner-take-all dynamics through signal-competition for gain. This physical circuit extracts what is mathematically referred to as the largest principal component of its spatio-temporal input space. The circuit's practicality is demonstrated by its incorporation in an RF-photonic system. An unknown mixture of unknown microwave signals, received by an antenna array, constitutes the input to the system. The output electronically returns one of the original microwave signals. The front-end of the system down converts the 10 GHz microwave signals and amplifies them before the signals phase modulate optical beams. The optical carrier is suppressed from these beams so that it may not be considered as a signal itself to the autotuning filter. The suppression is achieved with two-beam coupling in a single photorefractive crystal. The filter extracts the more intense of the signals present on the carrier-suppressed input beams. The detection of the extracted signal restores the microwave signal to an electronic form. The system, without the receiving antenna array, is packaged in a 13 x 18 x 6″ briefcase. Its power consumption equals that

  18. Simultaneous all-optical digital comparator and dual-directional half-subtractor for two-input 40 Gbit/s DPSK signals employing SOAs

    NASA Astrophysics Data System (ADS)

    Zhang, Yin; Lei, Lei; Dong, Jianji; Zhang, Xinliang

    2012-02-01

    A module of simultaneous implementation of all-optical digital comparator and dual-directional half-subtractor is proposed. Proof-of-concept experiment is performed at 40 Gbit/s employing the four-wave mixing and cross gain modulation in three parallel semiconductor optical amplifiers. All output results with over 10 dB extinction ratios, clear and wide open eye diagrams, are obtained without using assistant/holding light beam. All-optical half-adder can also be obtained by adjusting the phase shifter of delay interferometer in the proposed module because of its inherent reconfigurability and flexibility. The module would be a promising digital logic elementary circuit in all-optical networks and computing systems.

  19. Wired and wireless convergent extended-reach optical access network using direct-detection of all-optical OFDM super-channel signal.

    PubMed

    Chow, C W; Yeh, C H; Sung, J Y; Hsu, C W

    2014-12-15

    We propose and demonstrate the feasibility of using all-optical orthogonal frequency division multiplexing (AO-OFDM) for the convergent optical wired and wireless access networks. AO-OFDM relies on all-optically generated orthogonal subcarriers; hence, high data rate (> 100 Gb/s) can be easily achieved without hitting the speed limit of electronic digital-to-analog and analog-to-digital converters (DAC/ADC). A proof-of-concept convergent access network using AO-OFDM super-channel (SC) is demonstrated supporting 40 - 100 Gb/s wired and gigabit/s 100 GHz millimeter-wave (MMW) ROF transmissions.

  20. Broadband true time delay for microwave signal processing, using slow light based on stimulated Brillouin scattering in optical fibers.

    PubMed

    Chin, Sanghoon; Thévenaz, Luc; Sancho, Juan; Sales, Salvador; Capmany, José; Berger, Perrine; Bourderionnet, Jérôme; Dolfi, Daniel

    2010-10-11

    We experimentally demonstrate a novel technique to process broadband microwave signals, using all-optically tunable true time delay in optical fibers. The configuration to achieve true time delay basically consists of two main stages: photonic RF phase shifter and slow light, based on stimulated Brillouin scattering in fibers. Dispersion properties of fibers are controlled, separately at optical carrier frequency and in the vicinity of microwave signal bandwidth. This way time delay induced within the signal bandwidth can be manipulated to correctly act as true time delay with a proper phase compensation introduced to the optical carrier. We completely analyzed the generated true time delay as a promising solution to feed phased array antenna for radar systems and to develop dynamically reconfigurable microwave photonic filters.

  1. All-optical phase discrimination using SOA.

    PubMed

    Power, Mark J; Webb, Roderick P; Manning, Robert J

    2013-11-04

    We describe the first experimental demonstration of a novel all-optical phase discrimination technique, which can separate the two orthogonal phase components of a signal onto different frequencies. This method exploits nonlinear mixing in a semiconductor optical amplifier (SOA) to separate a 10.65 Gbaud QPSK signal into two 10.65 Gb/s BPSK signals which are then demodulated using a delay interferometer (DI). Eye diagrams and spectral measurements verify correct operation and a conversion efficiency greater than 9 dB is observed on both output BPSK channels when compared with the input QPSK signal.

  2. All-optical reservoir computing.

    PubMed

    Duport, François; Schneider, Bendix; Smerieri, Anteo; Haelterman, Marc; Massar, Serge

    2012-09-24

    Reservoir Computing is a novel computing paradigm that uses a nonlinear recurrent dynamical system to carry out information processing. Recent electronic and optoelectronic Reservoir Computers based on an architecture with a single nonlinear node and a delay loop have shown performance on standardized tasks comparable to state-of-the-art digital implementations. Here we report an all-optical implementation of a Reservoir Computer, made of off-the-shelf components for optical telecommunications. It uses the saturation of a semiconductor optical amplifier as nonlinearity. The present work shows that, within the Reservoir Computing paradigm, all-optical computing with state-of-the-art performance is possible.

  3. Fast all-optical switch

    NASA Technical Reports Server (NTRS)

    Shay, Thomas M. (Inventor); Poliakov, Evgeni Y. (Inventor); Hazzard, David A. (Inventor)

    2001-01-01

    An apparatus and method wherein polarization rotation in alkali vapors or other mediums is used for all-optical switching and digital logic and where the rate of operation is proportional to the amplitude of the pump field. High rates of speed are accomplished by Rabi flopping of the atomic states using a continuously operating monochromatic atomic beam as the pump.

  4. Proposal for all-optical generation of multiple-frequency millimeter-wave signals for RoF system with multiple base stations using FWM in SOA.

    PubMed

    Zhang, Chongfu; Wang, Leyang; Qiu, Kun

    2011-07-18

    An approach for the multiple-frequency millimeter-wave (mm-wave) signals generation is proposed and demonstrated, specifically, which can be applied to a radio-over-fiber (RoF) system with multiple base stations (BSs). In this scheme, optical double sideband (ODSB) modulation is achieved using a Mach-Zehnder modulator (MZM) to generate the two-sideband signals. New frequencies of the optical signals are obtained by using four-wave mixing (FWM) in a semiconductor optical amplifier (SOA). At the BSs, two different frequencies are achieved using a comb optical filter (COF), and which then input a photodiode (PD) to generate the mm-wave signals with the frequencies of 20, 40 or 60 GHz for different BSs, by mixing of these frequencies components. Experimental results verify that the proposed multiple-frequency mm-wave signals generation scheme for a RoF system with multiple base stations can work properly.

  5. Scanning microwave-induced thermoacoustic tomography: signal, resolution, and contrast.

    PubMed

    Ku, G; Wang, L V

    2001-01-01

    Scanning thermoacoustic tomography was explored in the microwave region of the electromagnetic spectrum. Short microwave pulses were used to induce acoustic waves by thermoelastic expansion in biological tissues. Cross sections of tissue samples were imaged by a linear scan of the samples while a focused ultrasonic transducer detected the time-resolved thermoacoustic signals. Based on the microwave-absorption properties of normal and cancerous breast tissues, the piezoelectric signals in response to the thermoacoustic contrast were investigated over a wide range of electromagnetic frequencies and depths of tumor locations. The axial resolution is related to the temporal profile of the microwave pulses and to the impulse response of the ultrasonic transducer. The lateral resolution is related to the numerical aperture of the ultrasonic transducer as well as to the frequency spectra of the piezoelectric signals in the time window corresponding to the axial resolution. Gain compensation, counteracting the microwave attenuation, was applied to enhance the image contrast.

  6. Preliminary development of digital signal processing in microwave radiometers

    NASA Technical Reports Server (NTRS)

    Stanley, W. D.

    1980-01-01

    Topics covered involve a number of closely related tasks including: the development of several control loop and dynamic noise model computer programs for simulating microwave radiometer measurements; computer modeling of an existing stepped frequency radiometer in an effort to determine its optimum operational characteristics; investigation of the classical second order analog control loop to determine its ability to reduce the estimation error in a microwave radiometer; investigation of several digital signal processing unit designs; initiation of efforts to develop required hardware and software for implementation of the digital signal processing unit; and investigation of the general characteristics and peculiarities of digital processing noiselike microwave radiometer signals.

  7. All-optical wavelength conversion and five-channel multicasting for 20 Gbit/s QPSK signals in a silicon waveguide.

    PubMed

    Wang, Xiaoyan; Huang, Lingchen; Yi, Ke; Feng, Xianglian; Gao, Shiming

    2014-11-01

    Wavelength conversion and five-channel multicasting for 20  Gbit/s quadrature phase-shift keying signals have been experimentally demonstrated based on four-wave mixing in a silicon waveguide with digital coherent detection. The eye diagrams and constellation diagrams of the converted and multicasting idlers are successfully observed. Moreover, the bit-error rates (BERs) of the generated idlers are measured and the power penalties are all less than 0.7 dB at a BER of 3×10(-3).

  8. Signal processing device to control microwave output

    NASA Astrophysics Data System (ADS)

    Pinto, J. G.

    1989-08-01

    The development of an electronic device to control the operation of a commercial microwave oven is discussed. This device when installed in conjunction with the existing circuitry of SHARP MICROWAVE OVEN (model R-9524) is capable of automatically advancing through a sequence of thawing recipes programmed and stored in the memory bank of the oven. The device therefore eliminates or minimizes human operator action needed in previous prototype version of a blood thawing device.

  9. All optical binary delta-sigma modulator

    NASA Astrophysics Data System (ADS)

    Sayeh, Mohammad R.; Siahmakoun, Azad

    2005-09-01

    This paper describes a novel A/D converter called "Binary Delta-Sigma Modulator" (BDSM) which operates only with nonnegative signal with positive feedback and binary threshold. This important modification to the conventional delta-sigma modulator makes the high-speed (>100GHz) all-optical implementation possible. It has also the capability to modify its own sampling frequency as well as its input dynamic range. This adaptive feature helps designers to optimize the system performance under highly noisy environment and also manage the power consumption of the A/D converters.

  10. All-optical gates based on photonic crystal resonators

    NASA Astrophysics Data System (ADS)

    Moille, Grégory; De Rossi, Alfredo; Combrié, Sylvain

    2016-04-01

    We briefly review the technology of advanced nonlinear resonators for all-optical gating with a specific focus on the application of high-performance signal sampling and on the properties of III-V semiconductor photonic crystals

  11. Systems and methods for remote long standoff biometric identification using microwave cardiac signals

    NASA Technical Reports Server (NTRS)

    McGrath, William R. (Inventor); Talukder, Ashit (Inventor)

    2012-01-01

    Systems and methods for remote, long standoff biometric identification using microwave cardiac signals are provided. In one embodiment, the invention relates to a method for remote biometric identification using microwave cardiac signals, the method including generating and directing first microwave energy in a direction of a person, receiving microwave energy reflected from the person, the reflected microwave energy indicative of cardiac characteristics of the person, segmenting a signal indicative of the reflected microwave energy into a waveform including a plurality of heart beats, identifying patterns in the microwave heart beats waveform, and identifying the person based on the identified patterns and a stored microwave heart beats waveform.

  12. High speed all optical networks

    NASA Technical Reports Server (NTRS)

    Chlamtac, Imrich; Ganz, Aura

    1990-01-01

    An inherent problem of conventional point-to-point wide area network (WAN) architectures is that they cannot translate optical transmission bandwidth into comparable user available throughput due to the limiting electronic processing speed of the switching nodes. The first solution to wavelength division multiplexing (WDM) based WAN networks that overcomes this limitation is presented. The proposed Lightnet architecture takes into account the idiosyncrasies of WDM switching/transmission leading to an efficient and pragmatic solution. The Lightnet architecture trades the ample WDM bandwidth for a reduction in the number of processing stages and a simplification of each switching stage, leading to drastically increased effective network throughputs. The principle of the Lightnet architecture is the construction and use of virtual topology networks, embedded in the original network in the wavelength domain. For this construction Lightnets utilize the new concept of lightpaths which constitute the links of the virtual topology. Lightpaths are all-optical, multihop, paths in the network that allow data to be switched through intermediate nodes using high throughput passive optical switches. The use of the virtual topologies and the associated switching design introduce a number of new ideas, which are discussed in detail.

  13. Sensing feeble microwave signals via an optomechanical transducer

    NASA Astrophysics Data System (ADS)

    Zhang, Keye; Bariani, Francesco; Dong, Ying; Zhang, Weiping; Meystre, Pierre

    2015-05-01

    Due to their low energy content microwave signals at the single-photon level are extremely challenging to measure. Guided by recent progress in single-photon optomechanics and hybrid optomechanical systems, we propose a multimode optomechanical transducer that can detect intensities significantly below the single-photon level via off-resonant adiabatic transfer of the microwave signal to the optical frequency domain where the measurement is then performed. The influence of intrinsic quantum and thermal fluctuations on the performance of this detector are considered in detail. We acknowledge financial support from National Basic Research Program of China, NSF, ARO and the DARPA QuaSAR and ORCHID programs.

  14. All-optical fast random number generator.

    PubMed

    Li, Pu; Wang, Yun-Cai; Zhang, Jian-Zhong

    2010-09-13

    We propose a scheme of all-optical random number generator (RNG), which consists of an ultra-wide bandwidth (UWB) chaotic laser, an all-optical sampler and an all-optical comparator. Free from the electric-device bandwidth, it can generate 10Gbit/s random numbers in our simulation. The high-speed bit sequences can pass standard statistical tests for randomness after all-optical exclusive-or (XOR) operation.

  15. Photonic microwave signals with zeptosecond-level absolute timing noise

    NASA Astrophysics Data System (ADS)

    Xie, Xiaopeng; Bouchand, Romain; Nicolodi, Daniele; Giunta, Michele; Hänsel, Wolfgang; Lezius, Matthias; Joshi, Abhay; Datta, Shubhashish; Alexandre, Christophe; Lours, Michel; Tremblin, Pierre-Alain; Santarelli, Giorgio; Holzwarth, Ronald; Le Coq, Yann

    2017-01-01

    Photonic synthesis of radiofrequency (RF) waveforms revived the quest for unrivalled microwave purity because of its ability to convey the benefits of optics to the microwave world. In this work, we perform a high-fidelity transfer of frequency stability between an optical reference and a microwave signal via a low-noise fibre-based frequency comb and cutting-edge photodetection techniques. We demonstrate the generation of the purest microwave signal with a fractional frequency stability below 6.5 × 10-16 at 1 s and a timing noise floor below 41 zs Hz-1/2 (phase noise below -173 dBc Hz-1 for a 12 GHz carrier). This outperforms existing sources and promises a new era for state-of-the-art microwave generation. The characterization is achieved through a heterodyne cross-correlation scheme with the lowermost detection noise. This unprecedented level of purity can impact domains such as radar systems, telecommunications and time-frequency metrology. The measurement methods developed here can benefit the characterization of a broad range of signals.

  16. Photonics for microwave systems and ultra-wideband signal processing

    NASA Astrophysics Data System (ADS)

    Ng, W.

    2016-08-01

    The advantages of using the broadband and low-loss distribution attributes of photonics to enhance the signal processing and sensing capabilities of microwave systems are well known. In this paper, we review the progress made in the topical areas of true-time-delay beamsteering, photonic-assisted analog-to-digital conversion, RF-photonic filtering and link performances. We also provide an outlook on the emerging field of integrated microwave photonics (MWP) that promise to reduce the cost of MWP subsystems and components, while providing significantly improved form-factors for system insertion.

  17. Microwave oscillator with reduced phase noise by negative feedback incorporating microwave signals with suppressed carrier

    NASA Technical Reports Server (NTRS)

    Dick, G. J.; Saunders, J.

    1989-01-01

    Oscillator configurations which reduce the effect of 1/f noise sources for both direct feedback and stabilized local oscillator (STALO) circuits are developed and analyzed. By appropriate use of carrier suppression, a small signal is generated which suffers no loss of loop phase information or signal-to-noise ratio. This small signal can be amplified without degradation by multiplicative amplifier noise, and can be detected without saturation of the detector. Together with recent advances in microwave resonator Qs, these circuit improvements will make possible lower phase noise than can be presently achieved without the use of cryogenic devices.

  18. Microwave photonic delay line signal processing.

    PubMed

    Diehl, John F; Singley, Joseph M; Sunderman, Christopher E; Urick, Vincent J

    2015-11-01

    This paper provides a path for the design of state-of-the-art fiber-optic delay lines for signal processing. The theoretical forms for various radio-frequency system performance metrics are derived for four modulation types: X- and Z-cut Mach-Zehnder modulators, a phase modulator with asymmetric Mach-Zehnder interferometer, and a polarization modulator with control waveplate and polarizing beam splitter. Each modulation type is considered to cover the current and future needs for ideal system designs. System gain, compression point, and third-order output intercept point are derived from the transfer matrices for each modulation type. A discussion of optical amplifier placement and fiber-effect mitigation is offered. The paper concludes by detailing two high-performance delay lines, built for unique applications, that exhibit performance levels an order of magnitude better than commercial delay lines. This paper should serve as a guide to maximizing the performance of future systems and offer a look into current and future research being done to further improve photonics technologies.

  19. Measuring Radiofrequency and Microwave Radiation from Varying Signal Strengths

    NASA Technical Reports Server (NTRS)

    Davis, Bette; Gaul, W. C.

    2007-01-01

    This viewgraph presentation discusses the process of measuring radiofrequency and microwave radiation from various signal strengths. The topics include: 1) Limits and Guidelines; 2) Typical Variable Standard (IEEE) Frequency Dependent; 3) FCC Standard 47 CFR 1.1310; 4) Compliance Follows Unity Rule; 5) Multiple Sources Contribute; 6) Types of RF Signals; 7) Interfering Radiations; 8) Different Frequencies Different Powers; 9) Power Summing - Peak Power; 10) Contribution from Various Single Sources; 11) Total Power from Multiple Sources; 12) Are You Out of Compliance?; and 13) In Compliance.

  20. Cosmic microwave background polarization signals from tangled magnetic fields.

    PubMed

    Seshadri, T R; Subramanian, K

    2001-09-03

    Tangled, primordial cosmic magnetic fields create small rotational velocity perturbations on the last scattering surface of the cosmic microwave background radiation. For fields which redshift to a present value of B0 = 3 x 10(-9) G, these vector modes are shown to generate polarization anisotropies of order 0.1-4 microK on small angular scales (500signals result for n = 2 spectra. Unlike inflation generated, scalar modes, these signals are dominated by the odd parity, B-type polarization, which could help in their detection.

  1. All-optical flip-flop based on coupled SOA-PSW

    NASA Astrophysics Data System (ADS)

    Wang, Lina; Wang, Yongjun; Wu, Chen; Wang, Fu

    2016-12-01

    The semiconductor optical amplifier (SOA) has obvious advantages in all-optical signal processing, because of the simple structure, strong non-linearity, and easy integration. A variety of all-optical signal processing functions, such as all-optical wavelength conversion, all-optical logic gates and all-optical sampling, can be completed by SOA. So the SOA has been widespread concerned in the field of all-optical signal processing. Recently, the polarization rotation effect of SOA is receiving considerable interest, and many researchers have launched numerous research work utilizing this effect. In this paper, a new all-optical flip-flop structure using polarization switch (PSW) based on polarization rotation effect of SOA is presented.

  2. Photonic-assisted microwave signal multiplication and modulation using a silicon Mach–Zehnder modulator

    PubMed Central

    Long, Yun; Zhou, Linjie; Wang, Jian

    2016-01-01

    Photonic generation of microwave signal is obviously attractive for many prominent advantages, such as large bandwidth, low loss, and immunity to electromagnetic interference. Based on a single integrated silicon Mach–Zehnder modulator (MZM), we propose and experimentally demonstrate a simple and compact photonic scheme to enable frequency-multiplicated microwave signal. Using the fabricated integrated MZM, we also demonstrate the feasibility of microwave amplitude-shift keying (ASK) modulation based on integrated photonic approach. In proof-of-concept experiments, 2-GHz frequency-doubled microwave signal is generated using a 1-GHz driving signal. 750-MHz/1-GHz frequency-tripled/quadrupled microwave signals are obtained with a driving signal of 250 MHz. In addition, a 50-Mb/s binary amplitude coded 1-GHz microwave signal is also successfully generated. PMID:26832305

  3. All-optical phase modulation for integrated interferometric biosensors.

    PubMed

    Dante, Stefania; Duval, Daphné; Sepúlveda, Borja; González-Guerrero, Ana Belen; Sendra, José Ramón; Lechuga, Laura M

    2012-03-26

    We present the theoretical and the experimental implementation of an all-optical phase modulation system in integrated Mach-Zehnder Interferometers to solve the drawbacks related to the periodic nature of the interferometric signal. Sensor phase is tuned by modulating the emission wavelength of low-cost commercial laser diodes by changing their output power. FFT deconvolution of the signal allows for direct phase readout, immune to sensitivity variations and to light intensity fluctuations. This simple phase modulation scheme increases the signal-to-noise ratio of the measurements in one order of magnitude, rendering in a sensor with a detection limit of 1.9·10⁻⁷ RIU. The viability of the all-optical modulation approach is demonstrated with an immunoassay detection as a biosensing proof of concept.

  4. Submicron bidirectional all-optical plasmonic switches

    PubMed Central

    Chen, Jianjun; Li, Zhi; Zhang, Xiang; Xiao, Jinghua; Gong, Qihuang

    2013-01-01

    Ultra-small all-optical switches are of importance in highly integrated optical communication and computing networks. However, the weak nonlinear light-matter interactions in natural materials present an enormous challenge to realize efficiently switching for the ultra-short interaction lengths. Here, we experimentally demonstrate a submicron bidirectional all-optical plasmonic switch with an asymmetric T-shape single slit. Sharp asymmetric spectra as well as significant field enhancements (about 18 times that in the conventional slit case) occur in the symmetry-breaking structure. Consequently, both of the surface plasmon polaritons propagating in the opposite directions on the metal surface are all-optically controlled inversely at the same time with the on/off switching ratios of >6 dB for the device lateral dimension of <1 μm. Moreover, in such a submicron structure, the coupling of free-space light and the on-chip bidirectional switching are integrated together. This submicron bidirectional all-optical switch may find important applications in the highly integrated plasmonic circuits. PMID:23486232

  5. Microwave Power Combiners for Signals of Arbitrary Amplitude

    NASA Technical Reports Server (NTRS)

    Conroy, Bruce; Hoppe, Daniel

    2009-01-01

    Schemes for combining power from coherent microwave sources of arbitrary (unequal or equal) amplitude have been proposed. Most prior microwave-power-combining schemes are limited to sources of equal amplitude. The basic principle of the schemes now proposed is to use quasi-optical components to manipulate the polarizations and phases of two arbitrary-amplitude input signals in such a way as to combine them into one output signal having a specified, fixed polarization. To combine power from more than two sources, one could use multiple powercombining stages based on this principle, feeding the outputs of lower-power stages as inputs to higher-power stages. Quasi-optical components suitable for implementing these schemes include grids of parallel wires, vane polarizers, and a variety of waveguide structures. For the sake of brevity, the remainder of this article illustrates the basic principle by focusing on one scheme in which a wire grid and two vane polarizers would be used. Wire grids are the key quasi-optical elements in many prior equal-power combiners. In somewhat oversimplified terms, a wire grid reflects an incident beam having an electric field parallel to the wires and passes an incident beam having an electric field perpendicular to the wires. In a typical prior equal-power combining scheme, one provides for two properly phased, equal-amplitude signals having mutually perpendicular linear polarizations to impinge from two mutually perpendicular directions on a wire grid in a plane oriented at an angle of 45 with respect to both beam axes. The wires in the grid are oriented to pass one of the incident beams straight through onto the output path and to reflect the other incident beam onto the output path along with the first-mentioned beam.

  6. All-Optical Fibre Networks For Coal Mines

    NASA Astrophysics Data System (ADS)

    Zientkiewicz, Jacek K.

    1987-09-01

    A topic of the paper is fiber-optic integrated network (FOIN) suited to the most hostile environments existing in coal mines. The use of optical fibres for transmission of mine instrumentation data offers the prospects of improved safety and immunity to electromagnetic interference (EMI). The feasibility of optically powered sensors has opened up new opportunities for research into optical signal processing architectures. This article discusses a new fibre-optic sensor network involving a time domain multiplexing(TDM)scheme and optical signal processing techniques. The pros and cons of different FOIN topologies with respect to coal mine applications are considered. The emphasis has been placed on a recently developed all-optical fibre network using spread spectrum code division multiple access (COMA) techniques. The all-optical networks have applications in explosive environments where electrical isolation is required.

  7. Progress towards interaction-free all-optical devices

    NASA Astrophysics Data System (ADS)

    Strekalov, Dmitry V.; Kowligy, Abijith S.; Huang, Yu-Ping; Kumar, Prem

    2014-06-01

    We present an all-optical control device in which coupling a weak control optical field into a high-Q lithium niobate whispering-gallery-mode microcavity decouples it from a signal field due to nonlinear optical interactions. This results in switching and modulation of the signal with low-power control pulses. In the quantum limit, the underlying nonlinear-optical process corresponds to the quantum Zeno blockade. Its "interaction-free" nature effectively alleviates loss and decoherence for the signal waves. This work therefore presents experimental progress towards acquiring large phase shifts with few photons or even at the single-photon level.

  8. Integrated waveguide Bragg gratings for microwave photonics signal processing.

    PubMed

    Burla, Maurizio; Cortés, Luis Romero; Li, Ming; Wang, Xu; Chrostowski, Lukas; Azaña, José

    2013-10-21

    Integrated Microwave photonics (IMWP) signal processing using Photonic Integrated Circuits (PICs) has attracted a great deal of attention in recent years as an enabling technology for a number of functionalities not attainable by purely microwave solutions. In this context, integrated waveguide Bragg grating (WBG) devices constitute a particularly attractive approach thanks to their compactness and flexibility in producing arbitrarily defined amplitude and phase responses, by directly acting on coupling coefficient and perturbations of the grating profile. In this article, we review recent advances in the field of integrated WBGs applied to MWP, analyzing the advantages leveraged by an integrated realization. We provide a perspective on the exciting possibilities offered by the silicon photonics platform in the field of MWP, potentially enabling integration of highly-complex active and passive functionalities with high yield on a single chip, with a particular focus on the use of WBGs as basic building blocks for linear filtering operations. We demonstrate the versatility of WBG-based devices by proposing and experimentally demonstrating a novel, continuously-tunable, integrated true-time-delay (TTD) line based on a very simple dual phase-shifted WBG (DPS-WBG).

  9. Generation of phase-coded microwave signals using a polarization-modulator-based photonic microwave phase shifter.

    PubMed

    Zhang, Yamei; Pan, Shilong

    2013-03-01

    A scheme for the generation of phase-coded microwave signals using an electrically tunable photonic microwave phase shifter is proposed and demonstrated. The photonic phase shifter is based on a single-sideband polarization modulator (PolM), and the tuning of the phase shifter is implemented by a second PolM. By introducing an RF signal to the first PolM and an electrical coding signal to the second PolM, a phase-coded microwave signal with binary phase codes or polyphase codes is achieved. An experiment is performed. The simple and flexible operation, high coding rate, large frequency range, excellent transmission performance, and high stability of the system is confirmed.

  10. All-optical vector atomic magnetometer.

    PubMed

    Patton, B; Zhivun, E; Hovde, D C; Budker, D

    2014-07-04

    We demonstrate an all-optical magnetometer capable of measuring the magnitude and direction of a magnetic field using nonlinear magneto-optical rotation in cesium vapor. Vector capability is added by effective modulation of the field along orthogonal axes and subsequent demodulation of the magnetic-resonance frequency. This modulation is provided by the ac Stark shift induced by circularly polarized laser beams. The sensor exhibits a demonstrated rms noise floor of ∼65  fT/√[Hz] in measurement of the field magnitude and 0.5  mrad/√[Hz] in the field direction; elimination of technical noise would improve these sensitivities to 12  fT/√[Hz] and 10  μrad/√[Hz], respectively. Applications for this all-optical vector magnetometer would include magnetically sensitive fundamental physics experiments, such as the search for a permanent electric dipole moment of the neutron.

  11. Pencil beam all-optical ultrasound imaging

    PubMed Central

    Alles, Erwin J.; Noimark, Sacha; Zhang, Edward; Beard, Paul C.; Desjardins, Adrien E.

    2016-01-01

    A miniature, directional fibre-optic acoustic source is presented that employs geometrical focussing to generate a nearly-collimated acoustic pencil beam. When paired with a fibre-optic acoustic detector, an all-optical ultrasound probe with an outer diameter of 2.5 mm is obtained that acquires a pulse-echo image line at each probe position without the need for image reconstruction. B-mode images can be acquired by translating the probe and concatenating the image lines, and artefacts resulting from probe positioning uncertainty are shown to be significantly lower than those observed for conventional synthetic aperture scanning of a non-directional acoustic source. The high image quality obtained for excised vascular tissue suggests that the all-optical ultrasound probe is ideally suited for in vivo, interventional applications. PMID:27699130

  12. Cost effective all-optical fractional OFDM receiver using an arrayed waveguide grating

    NASA Astrophysics Data System (ADS)

    Nagashima, T.; Cincotti, G.; Murakawa, T.; Shimizu, S.; Hasegawa, M.; Hattori, K.; Okuno, M.; Mino, S.; Himeno, A.; Wada, N.; Uenohara, H.; Konishi, T.

    2016-12-01

    We experimentally demonstrate the feasibility of implementing a cost effective all-optical fractional orthogonal frequency division multiplexing (AO-FrOFDM) receiver using an arrayed waveguide grating (AWG). The all-optical fractional Fourier transform at the receiver is implemented by modifying the second slab coupler from a conventional all-optical discrete Fourier transform AWG. The open eye diagrams obtained from the experimental results indicate that 12 × 10 Gbit/s DBPSK AO-FrOFDM signals were successfully demultiplexed.

  13. Preface to the special issue on "Integrated Microwave Photonic Signal Processing"

    NASA Astrophysics Data System (ADS)

    Azaña, José; Yao, Jianping

    2016-08-01

    As Guest Editors, we are pleased to introduce this special issue on ;Integrated Microwave Photonic Signal Processing; published by the Elsevier journal Optics Communications. Microwave photonics is a field of growing importance from both scientific and practical application perspectives. The field of microwave photonics is devoted to the study, development and application of optics-based techniques and technologies aimed to the generation, processing, control, characterization and/or distribution of microwave signals, including signals well into the millimeter-wave frequency range. The use of photonic technologies for these microwave applications translates into a number of key advantages, such as the possibility of dealing with high-frequency, wide bandwidth signals with minimal losses and reduced electromagnetic interferences, and the potential for enhanced reconfigurability. The central purpose of this special issue is to provide an overview of the state of the art of generation, processing and characterization technologies for high-frequency microwave signals. It is now widely accepted that the practical success of microwave photonics at a large scale will essentially depend on the realization of high-performance microwave-photonic signal-processing engines in compact and integrated formats, preferably on a chip. Thus, the focus of the issue is on techniques implemented using integrated photonic technologies, with the goal of providing an update of the most recent advances toward realization of this vision.

  14. All-optical nanomechanical heat engine.

    PubMed

    Dechant, Andreas; Kiesel, Nikolai; Lutz, Eric

    2015-05-08

    We propose and theoretically investigate a nanomechanical heat engine. We show how a levitated nanoparticle in an optical trap inside a cavity can be used to realize a Stirling cycle in the underdamped regime. The all-optical approach enables fast and flexible control of all thermodynamical parameters and the efficient optimization of the performance of the engine. We develop a systematic optimization procedure to determine optimal driving protocols. Further, we perform numerical simulations with realistic parameters and evaluate the maximum power and the corresponding efficiency.

  15. All-Optical Nanomechanical Heat Engine

    NASA Astrophysics Data System (ADS)

    Dechant, Andreas; Kiesel, Nikolai; Lutz, Eric

    2015-05-01

    We propose and theoretically investigate a nanomechanical heat engine. We show how a levitated nanoparticle in an optical trap inside a cavity can be used to realize a Stirling cycle in the underdamped regime. The all-optical approach enables fast and flexible control of all thermodynamical parameters and the efficient optimization of the performance of the engine. We develop a systematic optimization procedure to determine optimal driving protocols. Further, we perform numerical simulations with realistic parameters and evaluate the maximum power and the corresponding efficiency.

  16. All-optical symmetric ternary logic gate

    NASA Astrophysics Data System (ADS)

    Chattopadhyay, Tanay

    2010-09-01

    Symmetric ternary number (radix=3) has three logical states (1¯, 0, 1). It is very much useful in carry free arithmetical operation. Beside this, the logical operation using this type of number system is also effective in high speed computation and communication in multi-valued logic. In this literature all-optical circuits for three basic symmetrical ternary logical operations (inversion, MIN and MAX) are proposed and described. Numerical simulation verifies the theoretical model. In this present scheme the different ternary logical states are represented by different polarized state of light. Terahertz optical asymmetric demultiplexer (TOAD) based interferometric switch has been used categorically in this manuscript.

  17. Digitally encoded all-optical sensor multiplexing

    NASA Astrophysics Data System (ADS)

    Pervez, Anjum

    1992-01-01

    A digital, all-optical temperature sensor design concept based on optical sampling and digital encoding is presented. The proposed sensor generates 2M binary digital codewords of length M bits. The codewords are generated serially and, therefore, only a single output fiber line is required. A multiplexing scheme, which minimizes the power requirement per sensor array and facilitates a cost-effective digit regeneration for remote monitoring over long distance, is presented. The sensor arrays are used as building blocks to configure large scale sensor networks based on LAN topologies.

  18. Microwave signal processing in two-frequency domain for ROF systems implementation: training course

    NASA Astrophysics Data System (ADS)

    Morozov, Oleg G.; Morozov, Gennady A.

    2014-04-01

    This article is presented materials from two tutorials: "Optical two-frequency domain reflectometry1, 2" and "Microwave technologies in industry, living systems and telecommunications3". These materials were prepared for master training courses and listed in the "SPIE Optical Education Directory" for 2013/2014. The main its theme is microwave photonics. Microwave photonics has been defined as the study of photonic devices operating at microwave frequencies and their application to microwave and optical systems. Its initial rationale was to use the advantages of photonic technologies to provide functions in microwave systems that are very complex or even impossible to carry out directly in the radiofrequency domain. But microwave photonics is also succeeding in incorporating a variety of techniques used in microwave engineering to improve the performance of photonic communication networks and systems. Three parts of this chapter are devoted to applications and construction principles of systems forming microwave photonic filters, measuring instantaneous frequency of microwave heterodyne signals and characterizing stimulated Mandelstam- Brillouin scattering spectrum in ROF systems. The main emphasis is on the use of the two-frequency symmetric radiation, generated by the Il'in-Morozov's method4, in given systems. It is forming radiation for the synthesis of optical filters coefficients, it's application and processing determine the increase in the signal-to-noise ratio during heterodyne frequencies monitoring and characterization of nonlinear effects spectrum.

  19. Quantum-enabled temporal and spectral mode conversion of microwave signals

    NASA Astrophysics Data System (ADS)

    Andrews, R. W.; Reed, A. P.; Cicak, K.; Teufel, J. D.; Lehnert, K. W.

    2015-11-01

    Electromagnetic waves are ideal candidates for transmitting information in a quantum network as they can be routed rapidly and efficiently between locations using optical fibres or microwave cables. Yet linking quantum-enabled devices with cables has proved difficult because most cavity or circuit quantum electrodynamics systems used in quantum information processing can only absorb and emit signals with a specific frequency and temporal envelope. Here we show that the temporal and spectral content of microwave-frequency electromagnetic signals can be arbitrarily manipulated with a flexible aluminium drumhead embedded in a microwave circuit. The aluminium drumhead simultaneously forms a mechanical oscillator and a tunable capacitor. This device offers a way to build quantum microwave networks using separate and otherwise mismatched components. Furthermore, it will enable the preparation of non-classical states of motion by capturing non-classical microwave signals prepared by the most coherent circuit quantum electrodynamics systems.

  20. Quantum-enabled temporal and spectral mode conversion of microwave signals.

    PubMed

    Andrews, R W; Reed, A P; Cicak, K; Teufel, J D; Lehnert, K W

    2015-11-30

    Electromagnetic waves are ideal candidates for transmitting information in a quantum network as they can be routed rapidly and efficiently between locations using optical fibres or microwave cables. Yet linking quantum-enabled devices with cables has proved difficult because most cavity or circuit quantum electrodynamics systems used in quantum information processing can only absorb and emit signals with a specific frequency and temporal envelope. Here we show that the temporal and spectral content of microwave-frequency electromagnetic signals can be arbitrarily manipulated with a flexible aluminium drumhead embedded in a microwave circuit. The aluminium drumhead simultaneously forms a mechanical oscillator and a tunable capacitor. This device offers a way to build quantum microwave networks using separate and otherwise mismatched components. Furthermore, it will enable the preparation of non-classical states of motion by capturing non-classical microwave signals prepared by the most coherent circuit quantum electrodynamics systems.

  1. Rapidly reconfigurable all-optical universal logic gate

    DOEpatents

    Goddard, Lynford L.; Bond, Tiziana C.; Kallman, Jeffrey S.

    2010-09-07

    A new reconfigurable cascadable all-optical on-chip device is presented. The gate operates by combining the Vernier effect with a novel effect, the gain-index lever, to help shift the dominant lasing mode from a mode where the laser light is output at one facet to a mode where it is output at the other facet. Since the laser remains above threshold, the speed of the gate for logic operations as well as for reprogramming the function of the gate is primarily limited to the small signal optical modulation speed of the laser, which can be on the order of up to about tens of GHz. The gate can be rapidly and repeatedly reprogrammed to perform any of the basic digital logic operations by using an appropriate analog optical or electrical signal at the gate selection port. Other all-optical functionality includes wavelength conversion, signal duplication, threshold switching, analog to digital conversion, digital to analog conversion, signal routing, and environment sensing. Since each gate can perform different operations, the functionality of such a cascaded circuit grows exponentially.

  2. All-optical switching in Pharaonis phoborhodopsin protein molecules.

    PubMed

    Roy, Sukhdev; Kikukawa, Takashi; Sharma, Parag; Kamo, Naoki

    2006-09-01

    Low-power all-optical switching with pharaonis phoborhodopsin (ppR) protein is demonstrated based on nonlinear excited-state absorption at different wavelengths. A modulating pulsed 532-nm laser beam is shown to switch the transmission of a continuous-wave signal light beam at: 1) 390 nm; 2) 500 nm; 3) 560 nm; and 4) 600 nm, respectively. Simulations based on the rate equation approach considering all seven states in the ppR photocycle are in good agreement with experimental results. It is shown that the switching characteristics at 560 and 600 nm, respectively, can exhibit negative to positive switching. The switching characteristics at 500 nm can be inverted by increasing the signal beam intensity. The profile of switched signal beam is also sensitive to the modulating pulse frequency and signal beam intensity and wavelength. The switching characteristics are also shown to be sensitive to the lifetimes of ppR(M) and ppR(O) intermediates. The results show the applicability of ppR as a low-power wavelength tunable all-optical switch.

  3. All-optical OFDM network coding scheme for all-optical virtual private communication in PON

    NASA Astrophysics Data System (ADS)

    Li, Lijun; Gu, Rentao; Ji, Yuefeng; Bai, Lin; Huang, Zhitong

    2014-03-01

    A novel optical orthogonal frequency division multiplexing (OFDM) network coding scheme is proposed over passive optical network (PON) system. The proposed scheme for all-optical virtual private network (VPN) does not only improve transmission efficiency, but also realize full-duplex communication mode in a single fiber. Compared with the traditional all-optical VPN architectures, the all-optical OFDM network coding scheme can support higher speed, more flexible bandwidth allocation, and higher spectrum efficiency. In order to reduce the difficulty of alignment for encoding operation between inter-communication traffic, the width of OFDM subcarrier pulse is stretched in our proposed scheme. The feasibility of all-optical OFDM network coding scheme for VPN is verified, and the relevant simulation results show that the full-duplex inter-communication traffic stream can be transmitted successfully. Furthermore, the tolerance of misalignment existing in inter-ONUs traffic is investigated and analyzed for all-optical encoding operation, and the difficulty of pulse alignment is proved to be lower.

  4. All-optical central-frequency-programmable and bandwidth-tailorable radar

    PubMed Central

    Zou, Weiwen; Zhang, Hao; Long, Xin; Zhang, Siteng; Cui, Yuanjun; Chen, Jianping

    2016-01-01

    Radar has been widely used for military, security, and rescue purposes, and modern radar should be reconfigurable at multi-bands and have programmable central frequencies and considerable bandwidth agility. Microwave photonics or photonics-assisted radio-frequency technology is a unique solution to providing such capabilities. Here, we demonstrate an all-optical central-frequency-programmable and bandwidth-tailorable radar architecture that provides a coherent system and utilizes one mode-locked laser for both signal generation and reception. Heterodyning of two individually filtered optical pulses that are pre-chirped via wavelength-to-time mapping generates a wideband linearly chirped radar signal. The working bands can be flexibly tailored with the desired bandwidth at a user-preferred carrier frequency. Radar echoes are first modulated onto the pre-chirped optical pulse, which is also used for signal generation, and then stretched in time or compressed in frequency several fold based on the time-stretch principle. Thus, digitization is facilitated without loss of detection ability. We believe that our results demonstrate an innovative radar architecture with an ultra-high-range resolution. PMID:26795596

  5. All-optical central-frequency-programmable and bandwidth-tailorable radar

    NASA Astrophysics Data System (ADS)

    Zou, Weiwen; Zhang, Hao; Long, Xin; Zhang, Siteng; Cui, Yuanjun; Chen, Jianping

    2016-01-01

    Radar has been widely used for military, security, and rescue purposes, and modern radar should be reconfigurable at multi-bands and have programmable central frequencies and considerable bandwidth agility. Microwave photonics or photonics-assisted radio-frequency technology is a unique solution to providing such capabilities. Here, we demonstrate an all-optical central-frequency-programmable and bandwidth-tailorable radar architecture that provides a coherent system and utilizes one mode-locked laser for both signal generation and reception. Heterodyning of two individually filtered optical pulses that are pre-chirped via wavelength-to-time mapping generates a wideband linearly chirped radar signal. The working bands can be flexibly tailored with the desired bandwidth at a user-preferred carrier frequency. Radar echoes are first modulated onto the pre-chirped optical pulse, which is also used for signal generation, and then stretched in time or compressed in frequency several fold based on the time-stretch principle. Thus, digitization is facilitated without loss of detection ability. We believe that our results demonstrate an innovative radar architecture with an ultra-high-range resolution.

  6. Analysis of all-optical IP routers

    NASA Astrophysics Data System (ADS)

    Tamil, Lakshman S.; Masetti, Francesco B.; McDermott, Thomas C.; Castanon, Gerardo; Ge, Andrew; Tancevski, Ljubisa

    1998-10-01

    The increased data traffic experienced today and the projected increase in the data traffic in the future demand exploration of novel approaches to IP transport such as transport of IP traffic over optics. The bimodal nature of the IP traffic short packets which are typical of transactional-style flows and large packets or bursts which are encountered in the transport of large data blocks requires, design of routers that are capable of routing packets with variable lengths efficiently. In this paper, we discuss the design aspects of such all-optical IP-switches. The broadcast and select architecture is a prime candidate for implementing optical IP routers. Construction of optical routers with buffering, wavelength conversion and multipath routing are considered. The merits and demerits of all these cases and the effect of buffer size, wavelength conversion and multiple-path routing on the blocking probability and probability of packet loss are discussed.

  7. Microwave signal extraction from femtosecond mode-locked lasers with attosecond relative timing drift.

    PubMed

    Kim, Jungwon; Kärtner, Franz X

    2010-06-15

    We present a feedback-control method for suppression of excess phase noise in the optical-to-electronic conversion process involved in the extraction of microwave signals from femtosecond mode-locked lasers. A delay-locked loop based on drift-free phase detection with a differentially biased Sagnac loop is employed to eliminate low-frequency (e.g., <1 kHz) excess phase noise and drift in the regenerated microwave signals. A 10 GHz microwave signal is extracted from a 200 MHz repetition rate mode-locked laser with a relative rms timing jitter of 2.4 fs (integrated from 1 mHz to 1 MHz) and a relative rms timing drift of 0.84 fs (integrated over 8 h with 1 Hz bandwidth) between the optical pulse train and the extracted microwave signal.

  8. All-optical flip-flop and control methods thereof

    DOEpatents

    Maywar, Drew; Agrawal, Govind P.

    2010-03-23

    Embodiments of the invention pertain to remote optical control of holding beam-type, optical flip-flop devices, as well as to the devices themselves. All-optical SET and RE-SET control signals operate on a cw holding beam in a remote manner to vary the power of the holding beam between threshold switching values to enable flip-flop operation. Cross-gain modulation and cross-polarization modulation processes can be used to change the power of the holding beam.

  9. Nonlinear polarization rotation in a dispersion-flattened photonic-crystal fiber for ultrawideband (>100 nm) all-optical wavelength conversion of 10 Gbit/s nonreturn-to-zero signals.

    PubMed

    Kwok, C H; Chow, C W; Tsang, H K; Lin, Chinlon; Bjarklev, A

    2006-06-15

    We study the conversion bandwidth of the cross-polarization-modulation (XPoIM)-based wavelength conversion scheme with a dispersion-flattened highly nonlinear photonic-crystal fiber for signals with a nonreturn-to-zero (NRZ) modulation format. Both theoretical and experimental results show that the conversion bandwidth can be extended to cover a very wide band, including S-, C-, and L-bands for 10 Gbit/s NRZ signals (a total bandwidth of 120 nm is experimentally demonstrated). We also study the theoretical bandwidth limit for 40 Gbit/s NRZ signals. A significant extension of the conversion bandwidth using the XPoIM approach compared with the four-wave mixing approach previously reported is demonstrated.

  10. Dynamic modes of microwave signal autogeneration in a radio photonic ring generator

    NASA Astrophysics Data System (ADS)

    Kondrashov, A. V.; Ustinov, A. B.; Kalinikos, B. A.

    2017-02-01

    Dynamic modes of microwave signal autogeneration in a radio photonic generator have been investigated. The generator is a ring circuit with a low-pass filter and microwave amplifier in its microwave path. The optical path contains an optical fiber delay line. The generator demonstrates the periodical, chaotic, and noise dynamics. It has been shown that the correlation dimensionality of the random signal attractor in the chaotic generation mode saturates with increasing phase space dimensionality. Saturation is not observed in the noise-generation mode.

  11. A reconfigurable all-optical VPN based on XGM effect of SOA in WDM PON

    NASA Astrophysics Data System (ADS)

    Hu, Xiaofeng; Zhang, Liang; Cao, Pan; Wang, Tao; Su, Yikai

    2010-12-01

    We propose and experimentally demonstrate a reconfigurable all-optical VPN scheme enabling intercommunications among different ONUs in a WDM PON. Reconfiguration is realized by dynamically setting wavelength conversion of optical VPN signal using a SOA in the OLT.

  12. Polymeric components for all-optical networks

    NASA Astrophysics Data System (ADS)

    Eldada, Louay A.; Beeson, Karl W.; Pant, Deepti; Blomquist, Robert; Shacklette, Lawrence W.; McFarland, Michael J.

    2000-04-01

    All-optical networks that exhibit high speed, high capacity, scalability, configurability, and transparency are becoming a reality through the exploitation of the unique properties of fiber and integrated optics. An advanced polymeric waveguide technology was developed for affordable passive and active integrated optical elements that address the needs of these networks. We engineered high-performance organic polymers that can be readily made into photonic circuits of controlled numerical apertures and geometries. These materials are formed from highly-crosslinked acrylate monomers with specific linkages that determine properties such as flexibility, robustness, optical loss, thermal stability, and humidity resistance. These monomers are intermiscible, providing for precise continuous adjustment of the refractive index over a wide range. In polymer form, they exhibit state-of-the-art optical loss values, suppressed polarization effects, and exceptional environmental stability. A wide range of rigid and flexible substrates can be used. The devices we describe include demultiplexers, tunable wavelength filters, digital optical switches, and variable optical attenuators.

  13. The GALAXIE all-optical FEL project

    SciTech Connect

    Rosenzweig, J. B.; Arab, E.; Andonian, G.; Cahill, A.; Fitzmorris, K.; Fukusawa, A.; Hoang, P.; Jovanovic, I.; Marcus, G.; Marinelli, A.; Murokh, A.; Musumeci, P.; Naranjo, B.; O'Shea, B.; O'Shea, F.; Ovodenko, A.; Pogorelsky, I.; Putterman, S.; Roberts, K.; Shumail, M.; and others

    2012-12-21

    We describe a comprehensive project, funded under the DARPA AXiS program, to develop an all-optical table-top X-ray FEL based on dielectric acceleration and electromagnetic undulators, yielding a compact source of coherent X-rays for medical and related applications. The compactness of this source demands that high field (>GV/m) acceleration and undulation-inducing fields be employed, thus giving rise to the project's acronym: GV/m AcceLerator And X-ray Integrated Experiment (GALAXIE). There are numerous physics and technical hurdles to surmount in this ambitious scenario, and the integrated solutions include: a biharmonic photonic TW structure, 200 micron wavelength electromagnetic undulators, 5 {mu}m laser development, ultra-high brightness magnetized/asymmetric emittance electron beam generation, and SASE FEL operation. We describe the overall design philosophy of the project, the innovative approaches to addressing the challenges presented by the design, and the significant progress towards realization of these approaches in the nine months since project initialization.

  14. Practical application of a bidirectional microwave photonic filter: simultaneous transmission of analog TV signals

    NASA Astrophysics Data System (ADS)

    Correa-Mena, Ana Gabriela; Zaldívar-Huerta, Ignacio E.; Abril García, Jose Humberto; García-Juárez, Alejandro; Vera-Marquina, Alicia

    2016-10-01

    A practical application of a bidirectional microwave photonic filter (MPF) to transmit simultaneous analog TV signals coded on microwave carriers is experimentally demonstrated. The frequency response of the bidirectional MPF is obtained by the interaction of an externally modulated multimode laser diode emitting at 1.55 μm associated to the free-spectral range of the optical source, the chromatic dispersion parameter of the optical fiber, as well as the length of the optical link. The filtered microwave bandpass window generated around 2 GHz is used as electrical carrier in order to simultaneously transmit TV signals of 67.25 and 61.25 MHz in both directions. The obtained signal-to-noise ratios for the transmitted signals of 67.25 and 61.25 MHz are 37.62 and 44.77 dB, respectively.

  15. Photonic encryption using all optical logic.

    SciTech Connect

    Blansett, Ethan L.; Schroeppel, Richard Crabtree; Tang, Jason D.; Robertson, Perry J.; Vawter, Gregory Allen; Tarman, Thomas David; Pierson, Lyndon George

    2003-12-01

    With the build-out of large transport networks utilizing optical technologies, more and more capacity is being made available. Innovations in Dense Wave Division Multiplexing (DWDM) and the elimination of optical-electrical-optical conversions have brought on advances in communication speeds as we move into 10 Gigabit Ethernet and above. Of course, there is a need to encrypt data on these optical links as the data traverses public and private network backbones. Unfortunately, as the communications infrastructure becomes increasingly optical, advances in encryption (done electronically) have failed to keep up. This project examines the use of optical logic for implementing encryption in the photonic domain to achieve the requisite encryption rates. In order to realize photonic encryption designs, technology developed for electrical logic circuits must be translated to the photonic regime. This paper examines two classes of all optical logic (SEED, gain competition) and how each discrete logic element can be interconnected and cascaded to form an optical circuit. Because there is no known software that can model these devices at a circuit level, the functionality of the SEED and gain competition devices in an optical circuit were modeled in PSpice. PSpice allows modeling of the macro characteristics of the devices in context of a logic element as opposed to device level computational modeling. By representing light intensity as voltage, 'black box' models are generated that accurately represent the intensity response and logic levels in both technologies. By modeling the behavior at the systems level, one can incorporate systems design tools and a simulation environment to aid in the overall functional design. Each black box model of the SEED or gain competition device takes certain parameters (reflectance, intensity, input response), and models the optical ripple and time delay characteristics. These 'black box' models are interconnected and cascaded in an

  16. All-optical nonlinear plasmonic ring resonator switches

    NASA Astrophysics Data System (ADS)

    Nozhat, N.; Granpayeh, N.

    2014-11-01

    In this paper, all-optical nonlinear plasmonic ring resonator (PRR) switches containing 90o sharp and smooth bends have been proposed and numerically analyzed by the finite-difference time-domain method. Kerr nonlinear self-phase modulation (SPM) and cross-phase modulation (XPM) effects on the switching performance of the device have been studied. By applying a high-power lightwave, the signal can switch from one port to the other port due to the ON/OFF resonant states of the ring. We have shown that by utilizing the XPM effect, the output power ratio is improved by a factor of 2.5 and the required switching power is 31% of that of the case with only the SPM effect. Moreover, by utilizing sharp bend square-shaped ring resonators, the switching power is 10.4% lower than that of the smooth ones. The nonlinear PRR switches are suitable for application in photonic-integrated circuits as all-optical switches because of their nanoscale size and low required switching power.

  17. Integrated all-optical logic discriminators based on plasmonic bandgap engineering

    PubMed Central

    Lu, Cuicui; Hu, Xiaoyong; Yang, Hong; Gong, Qihuang

    2013-01-01

    Optical computing uses photons as information carriers, opening up the possibility for ultrahigh-speed and ultrawide-band information processing. Integrated all-optical logic devices are indispensible core components of optical computing systems. However, up to now, little experimental progress has been made in nanoscale all-optical logic discriminators, which have the function of discriminating and encoding incident light signals according to wavelength. Here, we report a strategy to realize a nanoscale all-optical logic discriminator based on plasmonic bandgap engineering in a planar plasmonic microstructure. Light signals falling within different operating wavelength ranges are differentiated and endowed with different logic state encodings. Compared with values previously reported, the operating bandwidth is enlarged by one order of magnitude. Also the SPP light source is integrated with the logic device while retaining its ultracompact size. This opens up a way to construct on-chip all-optical information processors and artificial intelligence systems. PMID:24071647

  18. All-optical sampling based on quantum-dot semiconductor optical amplifier

    NASA Astrophysics Data System (ADS)

    Wu, Chen; Wang, Yongjun; Wang, Lina

    2016-11-01

    In recent years, the all-optical signal processing system has become a hot research field of optical communication. This paper focused on the basic research of quantum-dot (QD) semiconductor optical amplifier (SOA) and studied its practical application to all-optical sampling. A multi-level dynamic physical model of QD-SOA is established, and its ultrafast dynamic characteristics are studied through theoretical and simulation research. For further study, an all-optical sampling scheme based on the nonlinear polarization rotation (NPR) effect of QD-SOA is also proposed. This paper analyzed the characteristics of optical switch window and investigated the influence of different control light pulses on switch performance. The presented optical sampling method has an important role in promoting the improvement of all-optical signal processing technology.

  19. All-optical D and T flip-flops based on polarization switch of SOA

    NASA Astrophysics Data System (ADS)

    Wang, Lina; Wang, Yongjun; Wu, Chen

    2016-11-01

    The semiconductor optical amplifier (SOA) plays an important role in the development of the all-optical signal processing because of the advantages of simple structure, easy integration and strong non-linearity. Especially the nonlinear polarization rotation effect of SOA is receiving considerable interest by many researchers nowadays. The all-optical flip-flop using the properties of SOA also obtains widespread attention by researchers, as all-optical flip-flop is an important part in the field of all-optical signal processing. In this paper, a new all-optical flip-flop structure using polarization switch (PSW) based on polarization rotation effect of SOA is presented. The main work of the paper is the simulation of all-optical logic gates and optical SR latch. The logic gate setup only uses one SOA, but it can get two different logic gates through a simulation. The extinction ratio of the logic gate is about 30dB. The structure of optical SR latch utilizes the two coupled polarization rotation switch of SOA. The structure of the flip-flop is based on these two parts. To demonstrate the feasibility of the structure, we analyze two types of flip-flops, including all-optical D and T flip-flops, whose clock pulse repetition rate is 1GHz with the pulse width of 0.3ns. The quality of all-optical flip-flop in this paper is measured by the falling and rising edge time. In the simulation, the falling edge time is about 50ps, while the rising edge time is higher than the falling edge time, because the gain increases slowly to the recovery time after the decrease of the gain of SOA. The results are useful for the development of all-optical flip-flop based on SOA.

  20. All-Optical Implementation of the Ant Colony Optimization Algorithm

    PubMed Central

    Hu, Wenchao; Wu, Kan; Shum, Perry Ping; Zheludev, Nikolay I.; Soci, Cesare

    2016-01-01

    We report all-optical implementation of the optimization algorithm for the famous “ant colony” problem. Ant colonies progressively optimize pathway to food discovered by one of the ants through identifying the discovered route with volatile chemicals (pheromones) secreted on the way back from the food deposit. Mathematically this is an important example of graph optimization problem with dynamically changing parameters. Using an optical network with nonlinear waveguides to represent the graph and a feedback loop, we experimentally show that photons traveling through the network behave like ants that dynamically modify the environment to find the shortest pathway to any chosen point in the graph. This proof-of-principle demonstration illustrates how transient nonlinearity in the optical system can be exploited to tackle complex optimization problems directly, on the hardware level, which may be used for self-routing of optical signals in transparent communication networks and energy flow in photonic systems. PMID:27222098

  1. All-Optical Implementation of the Ant Colony Optimization Algorithm

    NASA Astrophysics Data System (ADS)

    Hu, Wenchao; Wu, Kan; Shum, Perry Ping; Zheludev, Nikolay I.; Soci, Cesare

    2016-05-01

    We report all-optical implementation of the optimization algorithm for the famous “ant colony” problem. Ant colonies progressively optimize pathway to food discovered by one of the ants through identifying the discovered route with volatile chemicals (pheromones) secreted on the way back from the food deposit. Mathematically this is an important example of graph optimization problem with dynamically changing parameters. Using an optical network with nonlinear waveguides to represent the graph and a feedback loop, we experimentally show that photons traveling through the network behave like ants that dynamically modify the environment to find the shortest pathway to any chosen point in the graph. This proof-of-principle demonstration illustrates how transient nonlinearity in the optical system can be exploited to tackle complex optimization problems directly, on the hardware level, which may be used for self-routing of optical signals in transparent communication networks and energy flow in photonic systems.

  2. Tunable microwave signal generator with an optically-injected 1310 nm QD-DFB laser.

    PubMed

    Hurtado, Antonio; Mee, Jesse; Nami, Mohsen; Henning, Ian D; Adams, Michael J; Lester, Luke F

    2013-05-06

    Tunable microwave signal generation with frequencies ranging from below 1 GHz to values over 40 GHz is demonstrated experimentally with a 1310 nm Quantum Dot (QD) Distributed-Feedback (DFB) laser. Microwave signal generation is achieved using the period 1 dynamics induced in the QD DFB under optical injection. Continuous tuning in the positive detuning frequency range of the quantum dot's unique stability map is demonstrated. The simplicity of the experimental configuration offers promise for novel uses of these nanostructure lasers in Radio-over-Fiber (RoF) applications and future mobile networks.

  3. Frequency-time coherence for all-optical sampling without optical pulse source

    PubMed Central

    Preußler, Stefan; Raoof Mehrpoor, Gilda; Schneider, Thomas

    2016-01-01

    Sampling is the first step to convert an analogue optical signal into a digital electrical signal. The latter can be further processed and analysed by well-known electrical signal processing methods. Optical pulse sources like mode-locked lasers are commonly incorporated for all-optical sampling, but have several drawbacks. A novel approach for a simple all-optical sampling is to utilise the frequency-time coherence of each signal. The method is based on only using two coupled modulators driven with an electrical sine wave. Since no optical source is required, a simple integration in appropriate platforms, such as Silicon Photonics might be possible. The presented method grants all-optical sampling with electrically tunable bandwidth, repetition rate and time shift. PMID:27687495

  4. Rapidly Reconfigurable All-Optical Universal Logic Gates

    SciTech Connect

    Goddard, L L; Kallman, J S; Bond, T C

    2006-06-21

    We present designs and simulations for a highly cascadable, rapidly reconfigurable, all-optical, universal logic gate. We will discuss the gate's expected performance, e.g. speed, fanout, and contrast ratio, as a function of the device layout and biasing conditions. The gate is a three terminal on-chip device that consists of: (1) the input optical port, (2) the gate selection port, and (3) the output optical port. The device can be built monolithically using a standard multiple quantum well graded index separate confinement heterostructure laser configuration. The gate can be rapidly and repeatedly reprogrammed to perform any of the basic digital logic operations by using an appropriate analog electrical or optical signal at the gate selection port. Specifically, the same gate can be selected to execute one of the 2 basic unary operations (NOT or COPY), or one of the 6 binary operations (OR, XOR, AND, NOR, XNOR, or NAND), or one of the many logic operations involving more than two inputs. The speed of the gate for logic operations as well as for reprogramming the function of the gate is primarily limited to the small signal modulation speed of a laser, which can be on the order of tens of GHz. The reprogrammable nature of the universal gate offers maximum flexibility and interchangeability for the end user since the entire application of a photonic integrated circuit built from cascaded universal logic gates can be changed simply by adjusting the gate selection port signals.

  5. Long-term stable microwave signal extraction from mode-locked lasers.

    PubMed

    Kim, J; Ludwig, F; Felber, M; Kärtner, F X

    2007-07-09

    Long-term synchronization between two 10.225 GHz microwave signals at +10 dBm power level, locked to a 44.26 MHz repetition rate passively mode-locked fiber laser, is demonstrated using balanced optical-microwave phase detectors. The out-of-loop measurement result shows 12.8 fs relative timing jitter integrated from 10 Hz to 10 MHz. Long-term timing drift measurement shows 48 fs maximum deviation over one hour, mainly limited by drift of the out-of-loop characterization setup itself. To the best of our knowledge, this is the first time to demonstrate long-term (>1 hour) 3 mrad-level phase stability of a 10.225 GHz microwave signal extracted from a mode-locked laser.

  6. Temperature monitoring utilising thermoacoustic signals during pulsed microwave thermotherapy: a feasibility study.

    PubMed

    Lou, Cunguang; Xing, Da

    2010-01-01

    Thermotherapy is an attractive alternative to surgery and radiation therapy because of its ability to locally kill tumours while preserving surrounding normal tissues. An important part of successful thermotherapy is real-time temperature monitoring to control the area being heated while protecting normal tissue. The pulsed microwave absorbed by biological tissue can excite ultrasonic waves via thermoelastic expansion, while the magnitude of the acoustic signal is temperature-dependent. The goal of this work is to develop an approach for treatment monitoring of thermotherapy. The pulsed microwave serves as an acoustic excitation source as well as heating source. Temperature is real-time monitored by the magnitude of the thermoacoustic signals. Experiments were conducted in phantoms and fresh ex vivo tissues, an accuracy of 0.2 degrees C was obtained. This approach has the potential to be developed into a viable alternative to current clinical temperature monitoring device for microwave thermotherapy.

  7. Experimental Demonstration of Microwave Signal/Electric Thruster Plasma Interaction Effects

    NASA Technical Reports Server (NTRS)

    Zaman, Afroz J.; Lambert, Kevin M.; Curran, Frank M.

    1995-01-01

    An experiment was designed and conducted in the Electric Propulsion Laboratory of NASA Lewis Research Center to assess the impact of ion thruster exhaust plasma plume on electromagnetic signal propagation. A microwave transmission experiment was set up inside the propulsion test bed using a pair of broadband horn antennas and a 30 cm 2.3 kW ion thruster. Frequency of signal propagation covered from 6.5 to 18 GHz range. The stainless steel test bed when enclosed can be depressurized to simulate a near vacuum environment. A pulsed CW system with gating hardware was utilized to eliminate multiple chamber reflections from the test signal. Microwave signal was transmitted and received between the two hours when the thruster was operating at a given power level in such a way that the signal propagation path crossed directly through the plume volume. Signal attenuation and phase shift due to the plume was measured for the entire frequency band. Results for this worst case configuration simulation indicate that the effects of the ion thruster plume on microwave signals is a negligible attenuation (within 0.15 dB) and a small phase shift (within 8 deg.). This paper describes the detailed experiment and presents some of the results.

  8. Specific features of waveguide heating due to transmission of high-power microwave signals

    NASA Astrophysics Data System (ADS)

    Kudryavtsev, I. V.; Gotselyuk, O. B.; Novikov, E. S.; Demin, V. G.

    2017-01-01

    Waveguide heating due to transmission of microwave signals is studied. Mathematical models are developed to evaluate heat liberation, and differential equations of thermal balance are derived with allowance for different working conditions of waveguides. The results prove the necessity of the further study of the effect of heat liberation in waveguides on strength and functional characteristics.

  9. High-Dynamic-Range Fiber-Optic Link For Microwave Signals

    NASA Technical Reports Server (NTRS)

    Logan, Ronald T., Jr.; Lutes, George F.

    1992-01-01

    Ultrastable fiber-optic communications system transmits microwave signals between antenna sites of Deep Space Network (DSN) and central processing station several kilometers away. Permits relocation of critical components from front-end areas of DSN antennas to central location, permitting radio-frequency (RF) antenna arraying, improving DSN flexibility, maintainability, and system performance. Also useful in commercial analog and digital communications.

  10. Design of microwave signal source for CS chip-scale atomic clock

    NASA Astrophysics Data System (ADS)

    Lei, Ji; Zhi, Meng Hui; Li, Xin Wei; Liang, Tang; Qiao, Dong Hai

    2017-03-01

    Nowadays, some countries have already invented chip-scale atomic clock (CSAC) based on coherent population trapping (CPT), and it has been applied in every areas. According to its working principle, the microwave signal source is one of the decisive factors affecting its stability. Usually the microwave signal source is a phase-locked loop circuit, it mainly includes a frequency synthesizer, a voltage controlled oscillator (VCO) and a loop filter. This paper aims to develop a microwave signal source for Cs CSAC. First, a VCO should be designed, in order to validate the characteristic of the designed VCO, the VCO needs to be tested at high and low temperatures, and the results show that it has good stability of high and low temperatures. Second, for the purpose of verifying that the design and production consistency of the VCO are in good condition, 1000 VCOs are test, respectively. The statistical distribution of the phase noise at 1 kHz offset would be painted a curve. Finally, the designed VCO (PN: 61.01dBc/Hz@1kHz) will be applied in phase-locked loop, the test results show that the phase noise is ‑83.57dBc/Hz@300Hz, it is much better than ‑43dBc/Hz@300Hz which is the spec of CSAC. If the microwave signal source would be used in CSAC, its stability would be greatly improved.

  11. Optical Square-Wave Clock Generation Based on an All-Optical Flip-Flop

    SciTech Connect

    Kaplan, A.M.; Agrawal, G.P.; Maywar, D.N.

    2010-03-10

    We demonstrate optical square-wave clock generation based on an all-optical flip-flop. The bistable output power from a resonant-type semiconductor optical amplifier (SOA) is switched ON and OFF by modulating its input with its output via cross-gain modulation in a traveling-wave SOA. All active components are driven by dc currents, and the wavelength and clock frequency are selectable. A clock frequency of 3.5 MHz is demonstrated, limited by the time of flight between bulk optical components. Optical square-wave clock signals are promising for applications in photonic integrated circuits and all-optical signal processing.

  12. Photonic processing and realization of an all-optical digital comparator based on semiconductor optical amplifiers

    NASA Astrophysics Data System (ADS)

    Singh, Simranjit; Kaur, Ramandeep; Kaler, Rajinder Singh

    2015-01-01

    A module of an all-optical 2-bit comparator is analyzed and implemented using semiconductor optical amplifiers (SOAs). By employing SOA-based cross phase modulation, the optical XNOR logic is used to get an A=B output signal, where as AB¯ and A¯B> logics operations are used to realize A>B and Asignals, respectively. All input output bit operations results along with the wide open eye diagrams are obtained. It is suggested that the proposed system would be promising in all-optical high speed networks and computing systems.

  13. Method for making a micromachined microwave signal control device

    DOEpatents

    Forman, Michael A [Mountain House, CA

    2011-02-15

    A method for fabricating a signal controller, e.g., a filter or a switch, for a coplanar waveguide during the LIGA fabrication process of the waveguide. Both patterns for the waveguide and patterns for the signal controllers are created on a mask. Radiation travels through the mask and reaches a photoresist layer on a substrate. The irradiated portions are removed and channels are formed on the substrate. A metal is filled into the channels to form the conductors of the waveguide and the signal controllers. Micromachined quasi-lumped elements are used alone or together as filters. The switch includes a comb drive, a spring, a metal plunger, and anchors.

  14. 10Gbit/s all-optical NRZ to RZ conversion based on TOAD

    NASA Astrophysics Data System (ADS)

    Yan, Yumei; Yin, Lina; Zhou, Yunfeng; Liu, Guoming; Wu, Jian; Lin, Jintong

    2006-01-01

    Future network will include wavelength division multiplexing (WDM) and optical time division multiplexing (OTDM) technologies. All-optical format conversion between their respective preferable data formats, non-return-to-zero (NRZ) and return-to-zero (RZ), may become an important technology. In this paper, 10Gbit/s all-optical NRZ-to-RZ conversion is demonstrated based on terahertz optical asymmetric demultiplexer (TOAD) using clock all-optically recovered from the NRZ signal for the first time. The clock component is enhanced in an SOA and the pseudo-return-to-zero (PRZ) signal is filtered. The PRZ signal is input into an injection mode-locked fiber ring laser for clock recovery. The recovered clock and the NRZ signal are input into TOAD as pump signal and probe signal, respectively, and format conversion is performed. The quality of the converted RZ signal is determined by that of the recovered clock and the NRZ signal, whereas hardly influenced by gain recovery time of the SOA. In the experimental demonstration, the obtained RZ signal has an extinction ratio of 8.7dB and low pattern dependency. After conversion, the spectrum broadens obviously and shows multimode structure with spectrum interval of 0.08nm, which matches with the bit rate 10Gbit/s. Furthermore, this format conversion method has some tolerance on the pattern dependency of the clock signal.

  15. Dependence of microwave-excitation signal parameters on frequency stability of caesium atomic clock

    NASA Astrophysics Data System (ADS)

    Petrov, A. A.; Davydov, V. V.; Vologdin, V. A.; Zalyotov, D. V.

    2015-11-01

    New scheme of the microwave - excitation signal for the caesium atomic clock is based on method of direct digital synthesis. The theoretical calculations and experimental research showed decrease step frequency tuning by several orders and improvement the spectral characteristics of the output signal of frequency synthesizer. A range of generated output frequencies is expanded, and the possibility of detuning the frequency of the neighboring resonance of spectral line that makes it possible to adjust the C-field in quantum frequency standard is implemented. Experimental research of the metrological characteristics of the quantum frequency standard on the atoms of caesium - 133 with new design scheme of the microwave - excitation signal showed improvement in daily frequency stability on 1.2*10-14.

  16. Photonic generation of frequency-sextupled microwave signal based on dual-polarization modulation without an optical filter

    NASA Astrophysics Data System (ADS)

    Zhu, Zihang; Zhao, Shanghong; Li, Xuan; Qu, Kun; Lin, Tao

    2017-01-01

    Frequency-sextupled microwave signal generation based on dual-polarization modulation using an electro-optic dual-parallel polarization modulator (DPPolM) without an optical filter is proposed. From a theoretical analysis, the frequency-sextupled microwave signal can be obtained by properly adjusting the polarization directions of the modulated optical signals, the powers and the phases of the microwave drive signals applied to the DPPolM. Simulation results show that a 24 GHz microwave signal with an optical sideband suppression ratio (OSSR) exceeding 31 dB and a radio frequency spurious suppression ratio (RFSSR) higher than 25 dB is generated from a 4 GHz microwave drive signal, which match well with the theoretical analysis. Furthermore, it is also proved to be valid that even if the microwave drive voltage, the phase difference, and the polarization direction of light wave deviate from the ideal values to a certain degree, the performance of the generated frequency-sextupled microwave signal is still acceptable.

  17. New Magnetic Materials and Phenomena for Radar and Microwave Signal Processing Devices - Bulk and Thin Film Ferrites and Metallic Films

    DTIC Science & Technology

    2009-02-15

    methods have been used to produce in-plane c-axis (IPCA) oriented barium ferrite (BaM) films on o-plane (1120) sapphire substrates with low microwave ...New magnetic materials and phenomena for radar and microwave signal processing devices - bulk and thin film ferrites and metallic films 6. AUTHOR(S...excitation properties in delay line structures. (173 words) 14. SUBJECT TERMS Microwave ferrites , yttrium iron garnet, hexagonal ferrites

  18. Immunotropic influence of 900 MHz microwave GSM signal on human blood immune cells activated in vitro.

    PubMed

    Stankiewicz, Wanda; Dabrowski, Marek P; Kubacki, Roman; Sobiczewska, Elzbieta; Szmigielski, Stanisław

    2006-01-01

    In an earlier study we reported that G(o) phase peripheral blood mononulclear cells (PBMC) exposed to low-level (SAR = 0.18 W/kg) pulse-modulated 1300 MHz microwaves and subsequently cultured, demonstrate changed immune activity (Dabrowski et al., 2003). We investigated whether cultured immune cells induced into the active phases of cell cycle (G(1), S) and then exposed to microwaves will also be sensitive to electromagnetic field. An anechoic chamber of our design containing a microplate with cultured cells and an antenna emitting microwaves (900 MHz simulated GSM signal, 27 V/m, SAR 0.024 W/kg) was placed inside the ASSAB incubator. The microcultures of PBMC exposed to microwaves demonstrated significantly higher response to mitogens and higher immunogenic activity of monocytes (LM index) than control cultures. LM index, described in detail elsewhere (Dabrowski et al., 2001), represents the monokine influence on lymphocyte mitogenic response. The results suggest that immune activity of responding lymphocytes and monocytes can be additionally intensified by 900 MHz microwaves.

  19. All-optical photoacoustic microscopy using a MEMS scanning mirror

    NASA Astrophysics Data System (ADS)

    Chen, Sung-Liang; Xie, Zhixing; Ling, Tao; Wei, Xunbin; Guo, L. Jay; Wang, Xueding

    2013-03-01

    It has been studied that a potential marker to obtain prognostic information about bladder cancer is tumor neoangiogenesis, which can be quantified by morphometric characteristics such as microvascular density. Photoacoustic microscopy (PAM) can render sensitive three-dimensional (3D) mapping of microvasculature, providing promise to evaluate the neoangiogenesis that is closely related to the diagnosis of bladder cancer. To ensure good image quality, it is desired to acquire bladder PAM images from its inside via the urethra, like conventional cystoscope. Previously, we demonstrated all-optical PAM systems using polymer microring resonators to detect photoacoustic signals and galvanometer mirrors for laser scanning. In this work, we build a miniature PAM system using a microelectromechanical systems (MEMS) scanning mirror, demonstrating a prototype of an endoscopic PAM head capable of high imaging quality of the bladder. The system has high resolutions of 17.5 μm in lateral direction and 19 μm in the axial direction at a distance of 5.4 mm. Images of printed grids and the 3D structure of microvasculature in animal bladders ex vivo by the system are demonstrated.

  20. A 16-channel flex circuit for cryogenic microwave signal transmission

    NASA Astrophysics Data System (ADS)

    McGarey, Patrick; Mani, Hamdi; Wheeler, Caleb; Groppi, Christopher

    2014-07-01

    Heterodyne focal plane arrays used in the terahertz (THz) regime currently require a discrete set of rigid coaxial cables for the transmission of individual intermediate frequency (IF) signals. Consequently, the size of an array is limited to ~10s of pixels due to limited physical space and the complexity of assembly. In order to achieve an array with ~1000 pixels or greater, new interconnections must be developed capable of carrying multiple IF signals on a single carrier which is flexible, robust to noise, and terminated with a high density RF connector. As an intermediate step to the development of a ~1000 pixel heterodyne focal plane array, the Kilopixel Array Pathfinder Project (KAPPa) has developed a 16 channel IF flex circuit. Initially, design simulations were performed to evaluate various means of high-frequency (1~10 GHz) signal transmission, including microstrip, stripline and coplanar waveguides. The method allowing for the closest signal spacing and greatest resistance to radio frequency interference (RFI) was determined to be stripline. Designs were considered where stripline transitioned to microstrip in order to terminate the signal. As microstrip transmission lines are sensitive to RFI, a design featuring just stripline was evaluated. In both the stripline-to-microstrip and stripline-only designs, a three-layer copper-coated polyimide substrate was used. Signal transitions were accomplished by a signal carrying "hot" via passing through a series of three conductive pads, similar to work by Leib et al. (2010). The transition design essentially mimics a coaxial line, where the radial distance between the pads and the ground plane is optimized in order to achieve desired impedances. In simulation, 50 Ohm impedances were achieved throughout, with crosstalk and return loss limited to -30dB. Terminations are made via an array of Corning Gilbert G3PO blind mate connectors, which are small enough to match the 6mm pixel pitch of the KAPPa focal plane unit

  1. [Analysis of microwave-induced thermoacoustic signals and research-development preprocessor].

    PubMed

    Wei, Yusen; Wang, Hua; Zhu, Xinya; Jiao, Teng; Yang, Guosheng

    2009-06-01

    According to the results of analyzing the microwave-induced thermoacoustic signals, the amplitude and frequency were estimated and the designing parameters of preprocessor were decided. Based on the parameters, the signals preprocessor was designed with the band pass frequency ranging from 50 KHz to 3MHz, the gain ranging from 55 dB to 105 dB and the output noise being 1.32 V when the input was zero and the gain was 105 dB. The de-noising method of thermoacoustic signals was also discussed. The signals can be picked up by the preprocessor combined with the digital multipoint average method. The amplitude of signals is only 5 microV or even less. The results indicated that the preprocessor can meet the needs of thermoacoustic signals acquisition in bandwidth, gain and noise control.

  2. Analysis of photo-stimulation and microwave stimulation effects on EEG signal using Higuchi's fractal dimension method

    NASA Astrophysics Data System (ADS)

    Lipping, T.; Olejarczyk, E.; Parts, M.

    2004-07-01

    The microwave radiation effects on EEG-signal have been studied by comparison with photo-stimulaton. The study of photos-stimulation effects at 16 Hz frequency and microwave radiation stimulation effects at 450 MHz modulated with 7 Hz frequency show fractal dimension increase.

  3. Phase-coherent all-optical frequency division by three

    SciTech Connect

    Lee, Dong-Hoon; Klein, Marvin E.; Meyn, Jan-Peter; Wallenstein, Richard; Gross, Petra; Boller, Klaus-Jochen

    2003-01-01

    The properties of all-optical phase-coherent frequency division by 3, based on a self-phase-locked continuous-wave (cw) optical parametric oscillator (OPO), are investigated theoretically and experimentally. The frequency to be divided is provided by a diode laser master-oscillator power-amplifier system operated at a wavelength of 812 nm and used as the pump source of the OPO. Optical self-phase-locking of the OPO signal and idler waves is achieved by mutual injection locking of the signal wave and the intracavity frequency-doubled idler wave. The OPO process and the second-harmonic generation of the idler wave are simultaneously phase matched through quasi-phase-matching using two periodically poled sections of different period manufactured within the same LiNbO{sub 3} crystal. An optical self-phase-locking range of up to 1 MHz is experimentally observed. The phase coherence of frequency division by three is measured via the phase stability of an interference pattern formed by the input and output waves of the OPO. The fractional frequency instability of the divider is measured to be smaller than 7.6x10{sup -14} for a measurement time of 10 s (resolution limited). The self-phase-locking characteristics of the cw OPO are theoretically investigated by analytically solving the coupled field equations in the steady-state regime. For the experimental parameters of the OPO, the calculations predict a locking range of 1.3 MHz and a fractional frequency instability of 1.6x10{sup -15}, in good agreement with the experimental results.

  4. Dynamics of an all-optical atomic spin gyroscope.

    PubMed

    Fang, Jiancheng; Wan, Shuangai; Yuan, Heng

    2013-10-20

    We present the transfer function of an all-optical atomic spin gyroscope through a series of differential equations and validate the transfer function by experimental test. A transfer function is the basis for further control system design. We build the differential equations based on a complete set of Bloch equations describing the all-optical atomic spin gyroscope, and obtain the transfer function through application of the Laplace transformation to these differential equations. Moreover, we experimentally validate the transfer function in an all-optical Cs-Xe129 atomic spin gyroscope through a series of step responses. This transfer function is convenient for analysis of the form of control system required. Furthermore, it is available for the design of the control system specifically to improve the performance of all-optical atomic spin gyroscopes.

  5. Demonstration of an all-optical routing decision circuit

    NASA Astrophysics Data System (ADS)

    Liu, Y.; Martinez, J. M.; Herrera, J.; Clavero, R.; Ramos, F.; Koonen, A. M. J.; Marti, J.; Dorren, H. J. S.

    2007-11-01

    The routing decision functionality by all-optically interconnecting semiconductor-based all-optical logic gates and flip-flops is demonstrated in the frame of an all-optical packet switching network. We experimentally show that the output of the all-optical 2-bit correlator is capable of toggling the states of the integrated flip-flop every 2.5 ns via an adaptation stage. High extinction ratios are obtained at the output of the flip-flop, which can be used to feed a high-speed wavelength converter to complete the routing functionality of the AOLS node. The potential integration of these SOA-MZI based devices make the proposed approach a very interesting solution for future packet switched optical networks.

  6. High-order all-optical differential equation solver based on microring resonators.

    PubMed

    Tan, Sisi; Xiang, Lei; Zou, Jinghui; Zhang, Qiang; Wu, Zhao; Yu, Yu; Dong, Jianji; Zhang, Xinliang

    2013-10-01

    We propose and experimentally demonstrate a feasible integrated scheme to solve all-optical differential equations using microring resonators (MRRs) that is capable of solving first- and second-order linear ordinary differential equations with different constant coefficients. Employing two cascaded MRRs with different radii, an excellent agreement between the numerical simulation and the experimental results is obtained. Due to the inherent merits of silicon-based devices for all-optical computing, such as low power consumption, small size, and high speed, this finding may motivate the development of integrated optical signal processors and further extend optical computing technologies.

  7. All-optical diode with photonic multilayers based on asymmetric light localization

    NASA Astrophysics Data System (ADS)

    Jin, Li; Zhou, Jun; Yang, Mingyang; Xue, Chunhua; He, Miao

    2011-03-01

    An all-optical diode (AOD) with structure (AB)m(BA)n(BBAA)k is proposed based on asymmetric light localization, and its optical bistability are numerically investigated by the nonlinear transfer matrix method. Research results show that the behavior of the AOD strongly depends on the period number m, n, and k, the transmission direction of the AOD is related to the values of m and n, while k affects the transmission contrast of the AOD. It is a significant reference for the design of all-optical signal processing devices.

  8. Application of bistable optical logic gate arrays to all-optical digital parallel processing

    NASA Astrophysics Data System (ADS)

    Walker, A. C.

    1986-05-01

    Arrays of bistable optical gates can form the basis of an all-optical digital parallel processor. Two classes of signal input geometry exist - on- and off-axis - and lead to distinctly different device characteristics. The optical implementation of multisignal fan-in to an array of intrinsically bistable optical gates using the more efficient off-axis option is discussed together with the construction of programmable read/write memories from optically bistable devices. Finally the design of a demonstration all-optical parallel processor incorporating these concepts is presented.

  9. Architecture of an all optical de-multiplexer for spatially multiplexed channels

    NASA Astrophysics Data System (ADS)

    Murshid, Syed H.; Finch, Michael F.; Lovell, Gregory L.

    2013-05-01

    Multiple channels of light can propagate through a multimode fiber without interfering with each other and can be independently detected at the output end of the fiber using spatial domain multiplexing (SDM). Each channel forms a separate concentric ring at the output. The typical single pin-diode structure cannot simultaneously detect and demultiplex the multiple channel propagation supported by the SDM architecture. An array of concentric circular pindiodes can be used to simultaneously detect and de-multiplex the SDM signals; however, an all optical solution is generally preferable. This paper presents simple architecture for an all optical SDM de-multiplexer.

  10. All optical logic operations using semiconductor optical amplifier based devices

    NASA Astrophysics Data System (ADS)

    Wang, Qiang

    High-speed optical processing technologies are essential for the construction of all-optical networks in the information era. In this Ph. D. thesis dissertation, essential mechanisms related to the semiconductor optical amplifier (SOA) based device such as the gain and phase dynamics when a short pulse in propagating inside SOA, and, all-optical Boolean function, XOR, AND and OR have been studied. In order to realize the all-optical logic using SOA, the nonlinear gain and phase dynamics in SOA need to be studied first. The experimental results of 10--90% gain recovery curve have been presented. The recovery time is related to the carrier lifetime of the SOA and it varies with gain compression and bias current. For pulse width of a few picosecond, intraband effects need to be considered. In the SOA, phase change is also induced when a short pulse is propagating inside SOA. Unlike the conventional way of estimating the phase shift using alpha factor, the maximum phase shift is obtained first, then the effective alpha factor is calculated. The experimental results of all optical Boolean function XOR and OR at 80 Gb/s are presented using SOA-MZI-DI and SOA-DI respectively. These are the highest operating speed that has been reported. The all optical AND operation at 40 Gb/s using SOA-MZI have also been reported here. The numerical simulation shows that the performance of these all-optical Boolean operations is limited by the carrier lifetime of the SOA. The Boolean functions are the first step towards all optical circuits. The designs of a parity checker and a pseudo-random binary sequence (PRBS) generator are demonstrated. The error analysis using quality factor and eye-diagram is also presented.

  11. Control of microwave signals using bichromatic electromechanically induced transparency in multimode circuit electromechanical systems

    NASA Astrophysics Data System (ADS)

    Cheng, Jiang; Yuanshun, Cui; Xintian, Bian; Xiaowei, Li; Guibin, Chen

    2016-05-01

    We theoretically investigate the tunable delay and advancement of microwave signals based on bichromatic electromechanically induced transparency in a three-mode circuit electromechanical system, where two nanomechanical resonators with closely spaced frequencies are independently coupled to a common microwave cavity. In the presence of a strong microwave pump field, we obtain two transparency windows accompanied by steep phase dispersion in the transmitted microwave probe field. The width of the transparency window and the group delay of the probe field can be controlled effectively by the power of the pump field. It is shown that the maximum group delay of 0.12 ms and the advancement of 0.27 ms can be obtained in the current experiments. Project supported by the National Natural Science Foundation of China (Grant Nos. 11304110 and 11174101), the Jiangsu Natural Science Foundation, China (Grant Nos. BK20130413 and BK2011411), and the Natural Science Foundation of Jiangsu Higher Education Institutions of China (Grant Nos. 13KJB140002 and 15KJB460004).

  12. Study of all-optical sampling using a semiconductor optical amplifier

    NASA Astrophysics Data System (ADS)

    Wu, Chen; Wang, Yongjun; Wang, Lina; Wang, Fu

    2017-03-01

    All-optical sampling is an important research content of all-optical signal processing. In recent years, the application of the semiconductor optical amplifier (SOA) in optical sampling has attracted lots of attention because of its small volume and large nonlinear coefficient. We propose an optical sampling model based on nonlinear polarization rotation effect of the SOA. The proposed scheme has the advantages of high sampling speed and small input pump power, and a transfer curve with good linearity was obtained through simulation. To evaluate the performance of sampling, we analyze the linearity and efficiency of sampling pulse considering the impact of pulse width and analog signal frequency. We achieve the sampling of analog signal to high frequency pulse and exchange the positions of probe light and pump light to study another sampling.

  13. Simple novel all-optical half-adder

    NASA Astrophysics Data System (ADS)

    Chen, Zhixin

    2010-04-01

    On the basis of Sagnac interferometric structure, a simple novel ultrafast scheme of all-optical half-adder is proposed. The structure comprises two of the same balanced terahertz optical asymmetric demultiplexers (TOADs). One TOAD is utilized to achieve an all-optical XOR gate, which is logic SUM. The other is utilized to obtain an all-optical AND gate, which is logic CARRY. Logical SUM and CARRY are simultaneously realized at 80 Gbit/s. Through numerical analysis, the operating characteristics of the scheme are illustrated at 80 Gbit/s. Furthermore, the carrier recovery time of the semiconductor optical amplifier is no longer a crucial parameter to restrict the operation speed of this scheme.

  14. All-optical pseudorandom bit sequences generator based on TOADs

    NASA Astrophysics Data System (ADS)

    Sun, Zhenchao; Wang, Zhi; Wu, Chongqing; Wang, Fu; Li, Qiang

    2016-03-01

    A scheme for all-optical pseudorandom bit sequences (PRBS) generator is demonstrated with optical logic gate 'XNOR' and all-optical wavelength converter based on cascaded Tera-Hertz Optical Asymmetric Demultiplexer (TOADs). Its feasibility is verified by generation of return-to-zero on-off keying (RZ-OOK) 263-1 PRBS at the speed of 1 Gb/s with 10% duty radio. The high randomness of ultra-long cycle PRBS is validated by successfully passing the standard benchmark test.

  15. Photonic generation of a phase-coded microwave signal based on a single dual-drive Mach-Zehnder modulator.

    PubMed

    Tang, Zhenzhou; Zhang, Tingting; Zhang, Fangzheng; Pan, Shilong

    2013-12-15

    A compact scheme for photonic generation of a phase-coded microwave signal using a dual-drive Mach-Zehnder modulator (DMZM) is proposed and experimentally demonstrated. In the proposed scheme, the radio frequency (RF) carrier and the coding signal are sent to the two RF ports of the DMZM, respectively. By properly setting the amplitude of the coding signal and the bias voltage of the DMZM, an exact π-phase-shift phase-coded microwave signal is generated. The proposed scheme has a simple structure since only a single DMZM is required. In addition, good frequency tunability is achieved because no frequency-dependent electrical devices or wavelength-dependent optical devices are applied. The feasibility of the proposed scheme is verified by experiment. 2 or 2.5 Gb/s phase-coded 10 and 20 GHz microwave signals are successfully generated.

  16. Plasmonic enhancement of ultrafast all-optical magnetization reversal

    NASA Astrophysics Data System (ADS)

    Kochergin, Vladimir; Neely, Lauren N.; Allin, Leigh J.; Kochergin, Eugene V.; Wang, Kang L.

    2011-10-01

    Ultrafast all optical magnetization switching in GdFeCo layers on the basis of Inverse Faraday Effect (IFE) was demonstrated recently and suggested as a possible path toward next generation magnetic data storage medium with much faster writing time. However, to date, the demonstrations of ultrafast all-optical magnetization switching were performed with powerful femtosecond lasers, hardly useful for practical applications in data storage and data processing. Here we show that utilization of IFE enhancement in plasmonic nanostructures enables fast all-optical magnetization switching with smaller/cheaper laser sources with longer pulse durations. Our modeling results predict significant enhancement of IFE around all major types of plasmonic nanostructures for a circularly polarized incident light. Unlike the IFE in uniform bulk materials, nonzero value of IFE is predicted in plasmonic nanostructures even with a linearly polarized excitation. Experimentally, all-optical magnetization switching at 20 times lower laser fluence and roughly 100 times lower value of laser fluence/pulse duration ratio is demonstrated in plasmonic samples to verify the model predictions. The path to achieve higher levels of enhancement experimentally is discussed.

  17. All-optical digital processor based on harmonic generation phenomena

    NASA Astrophysics Data System (ADS)

    Shcherbakov, Alexandre S.; Rakovsky, Vsevolod Y.

    1990-07-01

    Digital optical processors are designed to combine ultra- parallel data procesing capabilities of optical aystems cnd high accur&cy of performed computations. The ultimate limit of the processing rate can be anticipated from all-optical parcllel erchitecturea based on networks o logic gates using materials exibiting strong electronic nonlinearities with response times less than 1O seconds1.

  18. All-optical Landau-Zener tunneling in waveguide arrays.

    PubMed

    Fratalocchi, Andrea; Assanto, Gaetano

    2006-03-06

    We investigate Landau-Zener all-optical tunneling in a voltage-controlled waveguide array realized in undoped nematic liquid crystals. From the material governing equations we derive the original Zener model and demonstrate a novel approach to Floquet-band tunneling.

  19. All-optical metamaterial modulators: Fabrication, simulation and characterization

    NASA Astrophysics Data System (ADS)

    Ku, Zahyun

    Artificially structured composite metamaterials consist of sub-wavelength sized structures that exhibit unusual electromagnetic properties not found in nature. Since the first experimental verification in 2000, metamaterials have drawn considerable attention because of their broad range of potential applications. One of the most attractive features of metamaterials is to obtain negative refraction, termed left-handed materials or negative-index metamaterials, over a limited frequency band. Negative-index metamaterials at near infrared wavelength are fabricated with circular, elliptical and rectangular holes penetrating through metal/dielectric/metal films. All three negative-index metamaterial structures exhibit similar figure of merit; however, the transmission is higher for the negative-index metamaterial with rectangular holes as a result of an improved impedance match with the substrate-superstrate (air-glass) combination. In general, the processing procedure to fabricate the fishnet structured negative-index metamaterials is to define the hole-size using a polymetric material, usually by lithographically defining polymer posts, followed by deposition of the constitutive materials and dissolution of the polymer (liftoff processing). This processing (fabrication of posts: multi-layer deposition: liftoff) often gives rise to significant sidewall-angle because materials accumulate on the tops of the posts that define the structure, each successive film deposition has a somewhat larger aperture on the bottom metamaterial film, giving rise to a nonzero sidewall-angle and to optical bianisotropy. Finally, we demonstrate a nanometer-scale, sub-picosecond metamaterial device capable of over terabit/second all-optical communication in the near infrared spectrum. We achieve a 600 fs device response by utilizing a regime of sub-picosecond carrier dynamics in amorphous silicon and ˜70% modulation in a path length of only 124 nm by exploiting the strong nonlinearities in

  20. All-optical cryptography of M-QAM formats by using two-dimensional spectrally sliced keys.

    PubMed

    Abbade, Marcelo L F; Cvijetic, Milorad; Messani, Carlos A; Alves, Cleiton J; Tenenbaum, Stefan

    2015-05-10

    There has been an increased interest in enhancing the security of optical communications systems and networks. All-optical cryptography methods have been considered as an alternative to electronic data encryption. In this paper we propose and verify the use of a novel all-optical scheme based on cryptographic keys applied on the spectral signal for encryption of the M-QAM modulated data with bit rates of up to 200 gigabits per second.

  1. Spatial Division Multiplexed Microwave Signal processing by selective grating inscription in homogeneous multicore fibers

    PubMed Central

    Gasulla, Ivana; Barrera, David; Hervás, Javier; Sales, Salvador

    2017-01-01

    The use of Spatial Division Multiplexing for Microwave Photonics signal processing is proposed and experimentally demonstrated, for the first time to our knowledge, based on the selective inscription of Bragg gratings in homogeneous multicore fibers. The fabricated devices behave as sampled true time delay elements for radiofrequency signals offering a wide range of operation possibilities within the same optical fiber. The key to processing flexibility comes from the implementation of novel multi-cavity configurations by inscribing a variety of different fiber Bragg gratings along the different cores of a 7-core fiber. This entails the development of the first fabrication method to inscribe high-quality gratings characterized by arbitrary frequency spectra and located in arbitrary longitudinal positions along the individual cores of a multicore fiber. Our work opens the way towards the development of unique compact fiber-based solutions that enable the implementation of a wide variety of 2D (spatial and wavelength diversity) signal processing functionalities that will be key in future fiber-wireless communications scenarios. We envisage that Microwave Photonics systems and networks will benefit from this technology in terms of compactness, operation versatility and performance stability. PMID:28134304

  2. Spatial Division Multiplexed Microwave Signal processing by selective grating inscription in homogeneous multicore fibers.

    PubMed

    Gasulla, Ivana; Barrera, David; Hervás, Javier; Sales, Salvador

    2017-01-30

    The use of Spatial Division Multiplexing for Microwave Photonics signal processing is proposed and experimentally demonstrated, for the first time to our knowledge, based on the selective inscription of Bragg gratings in homogeneous multicore fibers. The fabricated devices behave as sampled true time delay elements for radiofrequency signals offering a wide range of operation possibilities within the same optical fiber. The key to processing flexibility comes from the implementation of novel multi-cavity configurations by inscribing a variety of different fiber Bragg gratings along the different cores of a 7-core fiber. This entails the development of the first fabrication method to inscribe high-quality gratings characterized by arbitrary frequency spectra and located in arbitrary longitudinal positions along the individual cores of a multicore fiber. Our work opens the way towards the development of unique compact fiber-based solutions that enable the implementation of a wide variety of 2D (spatial and wavelength diversity) signal processing functionalities that will be key in future fiber-wireless communications scenarios. We envisage that Microwave Photonics systems and networks will benefit from this technology in terms of compactness, operation versatility and performance stability.

  3. Spatial Division Multiplexed Microwave Signal processing by selective grating inscription in homogeneous multicore fibers

    NASA Astrophysics Data System (ADS)

    Gasulla, Ivana; Barrera, David; Hervás, Javier; Sales, Salvador

    2017-01-01

    The use of Spatial Division Multiplexing for Microwave Photonics signal processing is proposed and experimentally demonstrated, for the first time to our knowledge, based on the selective inscription of Bragg gratings in homogeneous multicore fibers. The fabricated devices behave as sampled true time delay elements for radiofrequency signals offering a wide range of operation possibilities within the same optical fiber. The key to processing flexibility comes from the implementation of novel multi-cavity configurations by inscribing a variety of different fiber Bragg gratings along the different cores of a 7-core fiber. This entails the development of the first fabrication method to inscribe high-quality gratings characterized by arbitrary frequency spectra and located in arbitrary longitudinal positions along the individual cores of a multicore fiber. Our work opens the way towards the development of unique compact fiber-based solutions that enable the implementation of a wide variety of 2D (spatial and wavelength diversity) signal processing functionalities that will be key in future fiber-wireless communications scenarios. We envisage that Microwave Photonics systems and networks will benefit from this technology in terms of compactness, operation versatility and performance stability.

  4. Detection of radio-frequency modulated optical signals by two and three terminal microwave devices

    NASA Technical Reports Server (NTRS)

    Bhasin, K. B.; Simons, R. N.; Wojtczuk, S.

    1987-01-01

    An interdigitated photoconductor (two terminal device) on GaAlAs/GaAs heterostructure was fabricated and tested by an electro-optical sampling technique. Further, the photoresponse of GaAlAs/GaAs HEMT (three terminal device) was obtained by illuminating the device with an optical signal modulated up to 8 GHz. Gain-bandwidth product, response time, and noise properties of photoconductor and HEMT devices were obtained. Monolithic integration of these photodetectors with GaAs microwave devices for optically controlled phased array antenna applications is discussed.

  5. All-optical switching structure based on a photonic crystal directional coupler

    NASA Astrophysics Data System (ADS)

    Cuesta-Soto, F.; Martínez, A.; García, J.; Ramos, F.; Sanchis, P.; Blasco, J.; Martí, J.

    2004-01-01

    A novel all-optical switching structure based on a photonic crystal directional coupler is proposed and analyzed. Efficient optical switching is achieved by modifying the refractive index of the coupling region between the coupled waveguides by means of an optical control signal that is confined in the central region. Small length (around 1.1 mm) and low optical power consumption (over 1.5 W) are the main features estimated for this switching structure.

  6. Large-signal microwave performance of GaN-based NDR diode oscillators

    NASA Astrophysics Data System (ADS)

    Alekseev, Egor; Pavlidis, Dimitris

    2000-06-01

    The GaN material parameters relevant to the negative differential resistance (NDR) devices are discussed, and their physical models based on the theoretical predictions and experimental device characteristics are introduced. Gunn diode design criteria were applied to design the GaN NDR diodes. A higher electrical strength of the GaN allowed operation with higher doping (˜10 17 cm -3) and at a higher bias (90 V for a 3 μm thick diode). The transient hydrodynamic simulations were used to carry out the harmonic power analysis of the GaN NDR diode oscillators in order to evaluate their large-signal microwave characteristics. The GaAs Gunn diode oscillators were also simulated for a comparison and verification purposes. The dependence of the oscillation frequency and output power on the GaN NDR diode design and operating conditions are reported. It was found that, due to the higher electron velocities and reduced time constants, GaN NDR diodes offered twice the frequency capability of the GaAs Gunn diodes (87 GHz vs. 40 GHz), while their output power density was 2×10 5 W/cm 2 compared with ˜10 3 W/cm 2 for the GaAs devices. The reported improvements in the microwave performance are supported by the high value of the GaN Pf2Z figure of merit, which is 50-100 times higher than the GaAs, indicating a strong potential of the GaN for the microwave signal generation.

  7. All-optical high performance graphene-photonic crystal switch

    NASA Astrophysics Data System (ADS)

    Hoseini, Mehrdad; Malekmohammad, Mohammad

    2017-01-01

    The all-optical switch is realized based on nonlinear transmission changes in Fano resonance of 2D photonic crystals (PhC) which enhances the light intensity on the graphene in PhC; and in this study, the graphene layer is used as the nonlinear material. The refractive index change of graphene layer leads to a shift in the Fano resonance frequency due to the input light intensity through the Kerr nonlinear effect. Through finite-difference time-domain simulation, it is found that the high performance of all-optical switching can be achieved by the designed structure with a threshold pump intensity as low as MW/cm2. This structure is featured by optical bistability. The obtained results are applicable in micro optical integrated circuits for modulators, switches and logic elements for optical computation.

  8. On-chip CMOS-compatible all-optical integrator

    PubMed Central

    Ferrera, M.; Park, Y.; Razzari, L.; Little, B. E.; Chu, S. T.; Morandotti, R.; Moss, D. J.; Azaña, J.

    2010-01-01

    All-optical circuits for computing and information processing could overcome the speed limitations intrinsic to electronics. However, in photonics, very few fundamental 'building blocks' equivalent to those used in multi-functional electronic circuits exist. In this study, we report the first all-optical temporal integrator in a monolithic, integrated platform. Our device—a lightwave 'capacitor-like' element based on a passive micro-ring resonator—performs the time integral of the complex field of an arbitrary optical waveform with a time resolution of a few picoseconds, corresponding to a processing speed of ∼200 GHz, and a 'hold' time approaching a nanosecond. This device, compatible with electronic technology (complementary metal-oxide semiconductor), will be one of the building blocks of next-generation ultrafast data-processing technology, enabling optical memories and real-time differential equation computing units. PMID:20975692

  9. Bufferless Ultra-High Speed All-Optical Packet Routing

    NASA Astrophysics Data System (ADS)

    Muttagi, Shrihari; Prince, Shanthi

    2011-10-01

    All-Optical network is still in adolescence to cope up with steep rise in data traffic at the backbone network. Routing of packets in optical network depends on the processing speed of the All-Optical routers, thus there is a need to enhance optical processing to curb the delay in packet forwarding unit. In the proposed scheme, the header processing takes place on fly, therefore processing delay is at its lower limit. The objective is to propose a framework which establishes high data rate transmission with least latency in data routing from source to destination. The Routing table and optical header pulses are converted into Pulse Position (PP) format, thus reducing the complexity and in turn the processing delay. Optical pulse matching is exercised which results in multi-output transmission. This results in ultra-high speed packet forwarding unit. In addition, this proposed scheme includes dispersion compensation unit, which makes the data reliable.

  10. Ultrafast all optical switching via tunable Fano interference.

    PubMed

    Wu, Jin-Hui; Gao, Jin-Yue; Xu, Ji-Hua; Silvestri, L; Artoni, M; La Rocca, G C; Bassani, F

    2005-07-29

    Tunneling induced quantum interference experienced by an incident probe in asymmetric double quantum wells can easily be modulated by means of an external control light beam. This phenomenon, which is here examined within the dressed-state picture, can be exploited to devise a novel all-optical ultrafast switch. For a suitably designed semiconductor heterostructure, the switch is found to exhibit frequency bandwidths of the order of 0.1 THz and response and recovery times of about 1 ps.

  11. Photonic generation of phase-stable and wideband chirped microwave signals based on phase-locked dual optical frequency combs.

    PubMed

    Tong, Yitian; Zhou, Qian; Han, Daming; Li, Baiyu; Xie, Weilin; Liu, Zhangweiyi; Qin, Jie; Wang, Xiaocheng; Dong, Yi; Hu, Weisheng

    2016-08-15

    A photonics-based scheme is presented for generating wideband and phase-stable chirped microwave signals based on two phase-locked combs with fixed and agile repetition rates. By tuning the difference of the two combs' repetition rates and extracting different order comb tones, a wideband linearly frequency-chirped microwave signal with flexible carrier frequency and chirped range is obtained. Owing to the scheme of dual-heterodyne phase transfer and phase-locked loop, extrinsic phase drift and noise induced by the separated optical paths is detected and suppressed efficiently. Linearly frequency-chirped microwave signals from 5 to 15 GHz and 237 to 247 GHz with 30 ms duration are achieved, respectively, contributing to the time-bandwidth product of 3×108. And less than 1.3×10-5 linearity errors (RMS) are also obtained.

  12. Measurement of heart rate variability and stress evaluation by using microwave reflectometric vital signal sensing.

    PubMed

    Nagae, Daisuke; Mase, Atsushi

    2010-09-01

    In this paper, we present two robust signal processing techniques for stress evaluation using a microwave reflectometric cardiopulmonary sensing instrument. These techniques enable the heart rate variability (HRV) to be recovered from measurements of body-surface dynamic motion, which is subsequently used for the stress evaluation. Specifically, two novel elements are introduced: one is a reconfiguration of the HRV from the cross-correlation function between a measurement signal and a template signal which is constructed by averaging periodic component over a measurement time. The other is a reconstruction of the HRV from the time variation of the heartbeat frequency; this is evaluated by a repetition of the maximum entropy method. These two signal processing techniques accomplish the reconstruction of the HRV, though they are completely different algorithms. For validations of our model, an experimental setup is presented and several sets of experimental data are analyzed using the two proposed signal processing techniques, which are subsequently used for the stress evaluation. The results presented herein are consistent with electrocardiogram data.

  13. Measurement of heart rate variability and stress evaluation by using microwave reflectometric vital signal sensing

    NASA Astrophysics Data System (ADS)

    Nagae, Daisuke; Mase, Atsushi

    2010-09-01

    In this paper, we present two robust signal processing techniques for stress evaluation using a microwave reflectometric cardiopulmonary sensing instrument. These techniques enable the heart rate variability (HRV) to be recovered from measurements of body-surface dynamic motion, which is subsequently used for the stress evaluation. Specifically, two novel elements are introduced: one is a reconfiguration of the HRV from the cross-correlation function between a measurement signal and a template signal which is constructed by averaging periodic component over a measurement time. The other is a reconstruction of the HRV from the time variation of the heartbeat frequency; this is evaluated by a repetition of the maximum entropy method. These two signal processing techniques accomplish the reconstruction of the HRV, though they are completely different algorithms. For validations of our model, an experimental setup is presented and several sets of experimental data are analyzed using the two proposed signal processing techniques, which are subsequently used for the stress evaluation. The results presented herein are consistent with electrocardiogram data.

  14. Performance improvement of optical RZ-receiver by utilizing an all-optical waveform converter

    NASA Astrophysics Data System (ADS)

    Matsuura, Motoharu; Kishi, Naoto; Miki, Tetsuya

    2005-06-01

    A practical receiver scheme with all-optical waveform conversion is proposed and demonstrated. To mitigate influence of the timing jitter of the received signal, the proposed receiver employs a semiconductor optical amplifier (SOA)-based waveform converter, which can generate signal pulses with a rectangular-like profile. We have evaluated the receiver performances of the conventional and proposed schemes. The receiver sensitivity improvement of 0.7 dB and the phase-margin enlargement of 60 % were simultaneously achieved in comparison with the conventional receiver scheme.

  15. All-optical XOR and NAND logic gates based on plasmonic nanoparticles

    NASA Astrophysics Data System (ADS)

    Nozhat, Najmeh; Alikomak, Hamid; Khodadadi, Maryam

    2017-06-01

    In this paper, all-optical XOR and NAND logic gates based on gold disk-shaped nanoparticles have been proposed. The proposed structure consists of a non-periodic array of disk-shaped nanoparticles that are placed on SiO2 substrate. The gates function is based on the constructive and destructive interferences between the input signals. For the NAND gate the phase difference between the input signals has been used to create a destructive interference. The most advantages of these structures are subwavelength dimensions and high contrast ratio of about 26 dB and 24 dB for the XOR and NAND logic gates, respectively.

  16. Resolution-enhanced all-optical analog-to-digital converter employing cascade optical quantization operation.

    PubMed

    Kang, Zhe; Zhang, Xianting; Yuan, Jinhui; Sang, Xinzhu; Wu, Qiang; Farrell, Gerald; Yu, Chongxiu

    2014-09-08

    In this paper, a cascade optical quantization scheme is proposed to realize all-optical analog-to-digital converter with efficiently enhanced quantization resolution and achievable high analog bandwidth of larger than 20 GHz. Employing the cascade structure of an unbalanced Mach-zehnder modulator and a specially designed optical directional coupler, we predict the enhancement of number-of-bits can be up to 1.59-bit. Simulation results show that a 25 GHz RF signal is efficiently digitalized with the signal-to-noise ratio of 33.58 dB and effective-number-of-bits of 5.28-bit.

  17. All-optical Fresnel lens in coherent media: controlling image with image.

    PubMed

    Zhao, L; Duan, Wenhui; Yelin, S F

    2011-01-17

    We theoretically explore an all-optical method for generating tunable diffractive Fresnel lenses in coherent media based on electromagnetically induced transparency. In this method, intensity-modulated images in coupling light fields can pattern the coherent media to induce the desired modulo-2π quadratic phase profiles for the lenses to diffract probe light fields. We characterize the focusing and imaging properties of the induced lenses. In particular, we show that the images in coupling fields can flexibly control the images in probe fields by diffraction, where large focal length tunability from 1 m to infinity and high output (∼ 88% diffraction efficiency) can be achieved. Additionally, we also find that the induced Fresnel lenses can be rapidly modulated with megahertz refresh rates using image-bearing square pulse trains in coupling fields. Our proposed lenses may find a wide range of applications for multimode all-optical signal processing in both the classical and quantum regimes.

  18. In-fiber all-optical fractional differentiator.

    PubMed

    Cuadrado-Laborde, C; Andrés, M V

    2009-03-15

    We demonstrate that an asymmetrical pi phase-shifted fiber Bragg grating operated in reflection can provide the required spectral response for implementing an all-optical fractional differentiator. There are different (but equivalent) ways to design it, e.g., by using different gratings lengths and keeping the same index modulation depth at both sides of the pi phase shift, or vice versa. Analytical expressions were found relating the fractional differentiator order with the grating parameters. The device shows a good accuracy calculating the fractional time derivatives of the complex field of an arbitrary input optical waveform. The introduced concept is supported by numerical simulations.

  19. Realization of an all optical exciton-polariton router

    SciTech Connect

    Marsault, Félix; Nguyen, Hai Son; Tanese, Dimitrii; Lemaître, Aristide; Galopin, Elisabeth; Sagnes, Isabelle; Amo, Alberto

    2015-11-16

    We report on the experimental realization of an all optical router for exciton-polaritons. This device is based on the design proposed by Flayac and Savenko [Appl. Phys. Lett. 103, 201105 (2013)], in which a zero-dimensional island is connected through tunnel barriers to two periodically modulated wires of different periods. Selective transmission of polaritons injected in the island, into either of the two wires, is achieved by tuning the energy of the island state across the band structure of the modulated wires. We demonstrate routing of ps polariton pulses using an optical control beam which controls the energy of the island quantum states, thanks to polariton-exciton interactions.

  20. All-optical processing in coherent nonlinear spectroscopy

    SciTech Connect

    Oron, Dan; Dudovich, Nirit; Silberberg, Yaron

    2004-08-01

    In spectroscopy, the fingerprint of a substance is usually comprised of a sequence of spectral lines with characteristic frequencies and strengths. Identification of substances often involves postprocessing, where the measured spectrum is compared with tabulated fingerprint spectra. Here we suggest a scheme for nonlinear spectroscopy, where, through coherent control of the nonlinear process, the information from the entire spectrum can be practically collected into a single coherent entity. We apply this for all-optical analysis of coherent Raman spectra and demonstrate enhanced detection and effective background suppression using coherent processing.

  1. All-optical photon echo on a chip

    NASA Astrophysics Data System (ADS)

    Moiseev, E. S.; Moiseev, S. A.

    2017-01-01

    We demonstrate that a photon echo can be implemented by all-optical means using an array of on-chip high-finesse ring cavities whose parameters are chirped in such a way as to support equidistant spectra of cavity modes. When launched into such a system, a classical or quantum optical signal—even a single-photon field—becomes distributed between individual cavities, giving rise to prominent coherence echo revivals at well-defined delay times, controlled by the chirp of cavity parameters. This effect enables long storage times for high-throughput broadband optical delay and quantum memory.

  2. All optical indentation probe for endoscopic diagnosis of ostheoarthritis

    NASA Astrophysics Data System (ADS)

    Marchi, G.; Jost, M.; Steinkopff, A.; Prein, C.; Aszodi, A.; Clausen-Schaumann, H.; Roths, J.

    2015-05-01

    A novel kind of miniaturized, all optical probe concept to measure the elasticity of biological tissues is here presented. The probe is based on fibre Bragg grating sensors (FBG) inscribed in optical fibres. The measurement procedure exploits the high strain sensitivity of Bragg gratings. A study on the reproducibility, reliability, and resolution of the sensor is presented and a first measurement on bovine cartilage tissue is reported. A linear elastic model of the cartilage has been used to analyse the data. The results indicate a good agreement with previous values given in the literature for micro-indentation.

  3. Nearly noiseless amplification of microwave signals with a Josephson parametric amplifier

    NASA Astrophysics Data System (ADS)

    Castellanos-Beltran, Manuel

    2009-03-01

    A degenerate parametric amplifier transforms an incident coherent state by amplifying one of its quadrature components while deamplifying the other. This transformation, when performed by an ideal parametric amplifier, is completely deterministic and reversible; therefore the amplifier in principle can be noiseless. We attempt to realize a noiseless amplifier of this type at microwave frequencies with a Josephson parametric amplifier (JPA). To this end, we have built a superconducting microwave cavity containing many dc-SQUIDs. This arrangement creates a non-linear medium in a cavity and it is closely analogous to an optical parametric amplifier. In my talk, I will describe the current performance of this circuit, where I show I can amplify signals with less added noise than a quantum-limited amplifier that amplifies both quadratures. In addition, the JPA also squeezes the electromagnetic vacuum fluctuations by 10 dB. Finally, I will discuss our effort to put two such amplifiers in series in order to undo the first stage of squeezing with a second stage of amplification, demonstrating that the amplification process is truly reversible.[4pt] M. A. Castellanos-Beltran, K. D. Irwin, G. C. Hilton, L. R. Vale and K. W. Lehnert, Nature Physics, published on line, http://dx.doi.org/10.1038/nphys1090 (2008).

  4. All-optical transistor- and diode-action and logic gates based on anisotropic nonlinear responsive liquid crystal.

    PubMed

    Wang, Cheng-Yu; Chen, Chun-Wei; Jau, Hung-Chang; Li, Cheng-Chang; Cheng, Chiao-Yu; Wang, Chun-Ta; Leng, Shi-Ee; Khoo, Iam-Choon; Lin, Tsung-Hsien

    2016-08-05

    In this paper, we show that anisotropic photosensitive nematic liquid crystals (PNLC) made by incorporating anisotropic absorbing dyes are promising candidates for constructing all-optical elements by virtue of the extraordinarily large optical nonlinearity of the nematic host. In particular, we have demonstrated several room-temperature 'prototype' PNLC-based all-optical devices such as optical diode, optical transistor and all primary logic gate operations (OR, AND, NOT) based on such optical transistor. Owing to the anisotropic absorption property and the optical activity of the twist alignment nematic cell, spatially non-reciprocal transmission response can be obtained within a sizeable optical isolation region of ~210 mW. Exploiting the same mechanisms, a tri-terminal configuration as an all-optical analogue of a bipolar junction transistor is fabricated. Its ability to be switched by an optical field enables us to realize an all-optical transistor and demonstrate cascadability, signal fan-out, logic restoration, and various logical gate operations such as OR, AND and NOT. Due to the possibility of synthesizing anisotropic dyes and wide ranging choice of liquid crystals nonlinear optical mechanisms, these all-optical operations can be optimized to have much lower thresholds and faster response speeds. The demonstrated capabilities of these devices have shown great potential in all-optical control system and photonic integrated circuits.

  5. All-optical transistor- and diode-action and logic gates based on anisotropic nonlinear responsive liquid crystal

    PubMed Central

    Wang, Cheng-Yu; Chen, Chun-Wei; Jau, Hung-Chang; Li, Cheng-Chang; Cheng, Chiao-Yu; Wang, Chun-Ta; Leng, Shi-Ee; Khoo, Iam-Choon; Lin, Tsung-Hsien

    2016-01-01

    In this paper, we show that anisotropic photosensitive nematic liquid crystals (PNLC) made by incorporating anisotropic absorbing dyes are promising candidates for constructing all-optical elements by virtue of the extraordinarily large optical nonlinearity of the nematic host. In particular, we have demonstrated several room-temperature ‘prototype’ PNLC-based all-optical devices such as optical diode, optical transistor and all primary logic gate operations (OR, AND, NOT) based on such optical transistor. Owing to the anisotropic absorption property and the optical activity of the twist alignment nematic cell, spatially non-reciprocal transmission response can be obtained within a sizeable optical isolation region of ~210 mW. Exploiting the same mechanisms, a tri-terminal configuration as an all-optical analogue of a bipolar junction transistor is fabricated. Its ability to be switched by an optical field enables us to realize an all-optical transistor and demonstrate cascadability, signal fan-out, logic restoration, and various logical gate operations such as OR, AND and NOT. Due to the possibility of synthesizing anisotropic dyes and wide ranging choice of liquid crystals nonlinear optical mechanisms, these all-optical operations can be optimized to have much lower thresholds and faster response speeds. The demonstrated capabilities of these devices have shown great potential in all-optical control system and photonic integrated circuits. PMID:27491391

  6. All-optical transistor- and diode-action and logic gates based on anisotropic nonlinear responsive liquid crystal

    NASA Astrophysics Data System (ADS)

    Wang, Cheng-Yu; Chen, Chun-Wei; Jau, Hung-Chang; Li, Cheng-Chang; Cheng, Chiao-Yu; Wang, Chun-Ta; Leng, Shi-Ee; Khoo, Iam-Choon; Lin, Tsung-Hsien

    2016-08-01

    In this paper, we show that anisotropic photosensitive nematic liquid crystals (PNLC) made by incorporating anisotropic absorbing dyes are promising candidates for constructing all-optical elements by virtue of the extraordinarily large optical nonlinearity of the nematic host. In particular, we have demonstrated several room-temperature ‘prototype’ PNLC-based all-optical devices such as optical diode, optical transistor and all primary logic gate operations (OR, AND, NOT) based on such optical transistor. Owing to the anisotropic absorption property and the optical activity of the twist alignment nematic cell, spatially non-reciprocal transmission response can be obtained within a sizeable optical isolation region of ~210 mW. Exploiting the same mechanisms, a tri-terminal configuration as an all-optical analogue of a bipolar junction transistor is fabricated. Its ability to be switched by an optical field enables us to realize an all-optical transistor and demonstrate cascadability, signal fan-out, logic restoration, and various logical gate operations such as OR, AND and NOT. Due to the possibility of synthesizing anisotropic dyes and wide ranging choice of liquid crystals nonlinear optical mechanisms, these all-optical operations can be optimized to have much lower thresholds and faster response speeds. The demonstrated capabilities of these devices have shown great potential in all-optical control system and photonic integrated circuits.

  7. All-optical switching in plant blue light photoreceptor phototropin.

    PubMed

    Roy, Sukhdev; Kulshrestha, Kapil

    2006-12-01

    We theoretically analyze all-optical switching in the recently characterized LOV2 domain from Avena sativa (oat) phot1 phototropin, a blue-light plant photoreceptor, based on nonlinear intensity-induced excited-state absorption. The transmission of a cw probe laser beam at 660 nm corresponding to the peak absorption of the first excited L-state, through the LOV2 sample, is switched by a pulsed pump laser beam at 442 nm that corresponds to the maximum initial D state absorption. The switching characteristics have been analyzed using the rate equation approach, considering all the three intermediate states and transitions in the LOV2 photocycle. It is shown that for a given pump pulse intensity, there is an optimum pump pulsewidth for which the switching contrast is maximum. It is shown that the probe laser beam can be completely switched off (100% modulation) by the pump laser beam at 50 kW/cm2 for a concentration of 1 mM with sample thickness of 5.5 mm. The switching characteristics are sensitive to various parameters such as concentration, rate constant of L-state, peak pump intensity and pump pulse width. At typical values, the switch-off and switch-on time is 1.6 and 22.3 micros, respectively. The switching characteristics have also been used to design all-optical NOT and the universal NOR and NAND logic gates.

  8. All-Optical Wavelength Conversion by Picosecond Burst Absorption in Colloidal PbS Quantum Dots.

    PubMed

    Geiregat, Pieter; Houtepen, Arjan J; Van Thourhout, Dries; Hens, Zeger

    2016-01-26

    All-optical approaches to change the wavelength of a data signal are considered more energy- and cost-effective than current wavelength conversion schemes that rely on back and forth switching between the electrical and optical domains. However, the lack of cost-effective materials with sufficiently adequate optoelectronic properties hampers the development of this so-called all-optical wavelength conversion. Here, we show that the interplay between intraband and band gap absorption in colloidal quantum dots leads to a very strong and ultrafast modulation of the light absorption after photoexcitation in which slow components linked to exciton recombination are eliminated. This approach enables all-optical wavelength conversion at rates matching state-of-the-art convertors in speed, yet with cost-effective solution-processable materials. Moreover, the stronger light-matter interaction allows for implementation in small-footprint devices with low switching energies. Being a generic property, the demonstrated effect opens a pathway toward low-power integrated photonics based on colloidal quantum dots as the enabling material.

  9. Chip-integrated ultrawide-band all-optical logic comparator in plasmonic circuits

    PubMed Central

    Lu, Cuicui; Hu, Xiaoyong; Yang, Hong; Gong, Qihuang

    2014-01-01

    Optical computing opens up the possibility for the realization of ultrahigh-speed and ultrawide-band information processing. Integrated all-optical logic comparator is one of the indispensable core components of optical computing systems. Unfortunately, up to now, no any nanoscale all-optical logic comparator suitable for on-chip integration applications has been realized experimentally. Here, we report a subtle and effective technical solution to circumvent the obstacles of inherent Ohmic losses of metal and limited propagation length of SPPs. A nanoscale all-optical logic comparator suitable for on-chip integration applications is realized in plasmonic circuits directly. The incident single-bit (or dual-bit) logic signals can be compared and the comparison results are endowed with different logic encodings. An ultrabroad operating wavelength range from 700 to 1000 nm, and an ultrahigh output logic-state contrast-ratio of more than 25 dB are realized experimentally. No high power requirement is needed. Though nanoscale SPP light source and the logic comparator device are integrated into the same plasmonic chip, an ultrasmall feature size is maintained. This work not only paves a way for the realization of complex logic device such as adders and multiplier, but also opens up the possibility for realizing quantum solid chips based on plasmonic circuits. PMID:24463956

  10. Chip-integrated ultrawide-band all-optical logic comparator in plasmonic circuits

    NASA Astrophysics Data System (ADS)

    Lu, Cuicui; Hu, Xiaoyong; Yang, Hong; Gong, Qihuang

    2014-01-01

    Optical computing opens up the possibility for the realization of ultrahigh-speed and ultrawide-band information processing. Integrated all-optical logic comparator is one of the indispensable core components of optical computing systems. Unfortunately, up to now, no any nanoscale all-optical logic comparator suitable for on-chip integration applications has been realized experimentally. Here, we report a subtle and effective technical solution to circumvent the obstacles of inherent Ohmic losses of metal and limited propagation length of SPPs. A nanoscale all-optical logic comparator suitable for on-chip integration applications is realized in plasmonic circuits directly. The incident single-bit (or dual-bit) logic signals can be compared and the comparison results are endowed with different logic encodings. An ultrabroad operating wavelength range from 700 to 1000 nm, and an ultrahigh output logic-state contrast-ratio of more than 25 dB are realized experimentally. No high power requirement is needed. Though nanoscale SPP light source and the logic comparator device are integrated into the same plasmonic chip, an ultrasmall feature size is maintained. This work not only paves a way for the realization of complex logic device such as adders and multiplier, but also opens up the possibility for realizing quantum solid chips based on plasmonic circuits.

  11. Chip-integrated ultrawide-band all-optical logic comparator in plasmonic circuits.

    PubMed

    Lu, Cuicui; Hu, Xiaoyong; Yang, Hong; Gong, Qihuang

    2014-01-27

    Optical computing opens up the possibility for the realization of ultrahigh-speed and ultrawide-band information processing. Integrated all-optical logic comparator is one of the indispensable core components of optical computing systems. Unfortunately, up to now, no any nanoscale all-optical logic comparator suitable for on-chip integration applications has been realized experimentally. Here, we report a subtle and effective technical solution to circumvent the obstacles of inherent Ohmic losses of metal and limited propagation length of SPPs. A nanoscale all-optical logic comparator suitable for on-chip integration applications is realized in plasmonic circuits directly. The incident single-bit (or dual-bit) logic signals can be compared and the comparison results are endowed with different logic encodings. An ultrabroad operating wavelength range from 700 to 1000 nm, and an ultrahigh output logic-state contrast-ratio of more than 25 dB are realized experimentally. No high power requirement is needed. Though nanoscale SPP light source and the logic comparator device are integrated into the same plasmonic chip, an ultrasmall feature size is maintained. This work not only paves a way for the realization of complex logic device such as adders and multiplier, but also opens up the possibility for realizing quantum solid chips based on plasmonic circuits.

  12. All-optical tuning of a magnetic-fluid-filled optofluidic ring resonator.

    PubMed

    Liu, Yang; Shi, Lei; Xu, Xinbiao; Zhao, Ping; Wang, Zheqi; Pu, Shengli; Zhang, Xinliang

    2014-08-21

    An all-optical tunable optofluidic ring resonator (OFRR) is proposed and experimentally demonstrated. The all-optical control of a silica microresonator is highly attractive, but it is difficult to realize because of the relatively weak Kerr effect and the absence of a plasma dispersion effect of silica. Here, we infuse a silica microcapillary-based optofluidic ring resonator with a magnetic fluid, into which pump light is injected by a fiber taper. Iron oxide nanoparticles dispersed in the magnetic fluid produce a strong pump light absorption, and this leads to a resonance shift of the silica microresonator due to the photothermal effect. To the best of our knowledge, this is the first scheme for all-optical tuning of an OFRR. A tuning sensitivity of up to 0.15 nm mW(-1) and a tuning range of 3.3 nm are achieved. With such excellent performance, the magnetic-fluid-filled OFRR has great potential in filtering, sensing, and signal processing applications.

  13. Some Signal Processing Techniques for Use in Broadband Time Domain Microwave Spectroscopy

    NASA Astrophysics Data System (ADS)

    Cooke, S. A.

    2016-06-01

    At the present time, in the typical broadband, time domain microwave spectroscopy experiment each free induction decay (FID) collected is on the order of 10^6 data points in length with a sampling rate on the order of 10-12 seconds per point. Traditionally, the FID is processed using a fast Fourier transform algorithm (FFT) with the resulting power spectrum used in ensuing spectral analyses. For use with the FFT algorithm we have implemented some pre- and post-processing techniques to improve the signal quality. These techniques include the use of Lissajous plots to ensure phase stability in signal addition, novel windowing functions, and also automated broadband phase corrections which allow the absorption spectrum to be used as a more highly resolved version of the traditional power spectrum (see figure). We have also implemented alternatives to the FFT algorithm for time domain signal processing including Hankel singular valued decomposition, a maximum entropy method, and wavelet transformations. Although these techniques are unlikely to be used in place of a fast Fourier transform we will demonstrate how each of these techniques may be used to augment the traditional FFT algorithm in regards to spectral analysis.

  14. Bidirectional Data Injection Operation of Hybrid Integrated SOA MZI All-Optical Wavelength Converter

    NASA Astrophysics Data System (ADS)

    Hattori, Masaharu; Nishimura, Kohsuke; Inohara, Ryo; Usami, Masashi

    2007-02-01

    A bidirectional data signal input scheme of a semiconductor optical amplifier Mach Zehnder interferometer (SOA MZI) wavelength converter was proposed and experimentally verified for a nonreturn-to-zero (NRZ)-format signal. Theoretical analyses reveal that it is possible to mitigate the patterning effect induced by cross-gain modulation (XGM) by utilizing the difference of the ratio between the XGM and cross-phase modulation on the injection directions of data signals. A hybrid integrated SOA MZI all-optical wavelength converter, in which the coupling loss between the SOA and the silica waveguide was as small as 1 dB owing to a unique active alignment technique, was used for the experiment. We have verified the superior characteristics of the proposed operation scheme for the first time. Error-free wavelength-conversion operation for an NRZ signal at 40 Gb/s was confirmed.

  15. All-optical switching via four-wave mixing Bragg scattering in a silicon platform

    NASA Astrophysics Data System (ADS)

    Zhao, Yun; Lombardo, David; Mathews, Jay; Agha, Imad

    2017-02-01

    We employ the process of non-degenerate four-wave mixing Bragg scattering to demonstrate all-optical control in a silicon platform. In our configuration, a strong, non-information-carrying pump is mixed with a weak control pump and an input signal in a silicon-on-insulator waveguide. Through the optical nonlinearity of this highly confining waveguide, the weak pump controls the wavelength conversion process from the signal to an idler, leading to a controlled depletion of the signal. The strong pump, on the other hand, plays the role of a constant bias. In this work, we show experimentally that it is possible to implement this low-power switching technique as a first step towards universal optical logic gates, and test the performance with random binary data. Even at very low powers, where the signal and control pump levels are almost equal, the eye-diagrams remain open, indicating a successful operation of the logic gates.

  16. Production and all-optical deceleration of molecular beams

    NASA Astrophysics Data System (ADS)

    Chen, Gary; Jayich, Andrew; Long, Xueping; Ransford, Anthony; Campbell, Wesley

    2015-05-01

    Ultracold molecules open up new opportunities in many areas of study, including many-body physics, quantum chemistry, quantum information, and precision measurements. Current methods cannot easily address the spontaneous decay of molecules into dark states without an amalgam of repump lasers. We present an alternative method to produce cold molecules. A cryogenic buffer gas beam (CBGB) is used to create an intense, slow, cold source of molecules. By using a CBGB for the production, we can quench vibrational modes that cannot be addressed with optical methods. This is then followed by an all-optical scheme using a single ultra-fast laser to decelerate the molecules and a continuous wave laser to cool the species. We have started experiments with strontium monohydride (SrH), but the proposed method should be applicable to a wide range of molecular species.

  17. Microscopic model for all optical switching in ferromagnets

    NASA Astrophysics Data System (ADS)

    Cornelissen, T. D.; Córdoba, R.; Koopmans, B.

    2016-04-01

    The microscopic mechanism behind the all optical switching (AOS) in ferromagnets has triggered intense scientific debate. Here, the microscopic three-temperature model is utilized to describe AOS in a perpendicularly magnetized ferromagnetic Co/Pt system. We demonstrate that AOS in such a ferromagnet can be explained with the Inverse Faraday Effect (IFE). The influence of the strength and lifetime of the IFE induced field pulse on the switching process are investigated. We found that because of strong spin-orbit coupling, the minimal lifetime of the IFE needed to obtain switching is of the order of 0.1 ps, which is shorter than previously assumed. Moreover, spatial images of the domain pattern after AOS in Co/Pt, as well as their dependence on applying an opposite magnetic field, are qualitatively reproduced.

  18. Graphene based All-Optical Spatial Terahertz Modulator

    PubMed Central

    Wen, Qi-Ye; Tian, Wei; Mao, Qi; Chen, Zhi; Liu, Wei-Wei; Yang, Qing-Hui; Sanderson, Matthew; Zhang, Huai-Wu

    2014-01-01

    We demonstrate an all-optical terahertz modulator based on single-layer graphene on germanium (GOG), which can be driven by a 1.55 μm CW laser with a low-level photodoping power. Both the static and dynamic THz transmission modulation experiments were carried out. A spectrally wide-band modulation of the THz transmission is obtained in a frequency range from 0.25 to 1 THz, and a modulation depth of 94% can be achieved if proper pump power is applied. The modulation speed of the modulator was measured to be ~200 KHz using a 340 GHz carrier. A theoretical model is proposed for the modulator and the calculation results indicate that the enhanced THz modulation is mainly due to the third order nonlinear effect in the optical conductivity of the graphene monolayer. PMID:25491194

  19. All-optical generation of surface plasmons in graphene

    NASA Astrophysics Data System (ADS)

    Constant, T. J.; Hornett, S. M.; Chang, D. E.; Hendry, E.

    2016-02-01

    Surface plasmons in graphene offer a compelling route to many useful photonic technologies. As a plasmonic material, graphene offers several intriguing properties, such as excellent electro-optic tunability, crystalline stability, large optical nonlinearities and extremely high electromagnetic field concentration. As such, recent demonstrations of surface plasmon excitation in graphene using near-field scattering of infrared light have received intense interest. Here we present an all-optical plasmon coupling scheme which takes advantage of the intrinsic nonlinear optical response of graphene. Free-space, visible light pulses are used to generate surface plasmons in a planar graphene sheet using difference frequency wave mixing to match both the wavevector and energy of the surface wave. By carefully controlling the phase matching conditions, we show that one can excite surface plasmons with a defined wavevector and direction across a large frequency range, with an estimated photon efficiency in our experiments approaching 10-5.

  20. Quantum mechanical interpretation of the ultrafast all optical spin switching.

    PubMed

    Murakami, Mitsuko; Babyak, Zach; Giocolo, Michael; Zhang, G P

    2017-03-08

    The all-optical spin switching induced by an intense (∼TW cm(-2)), near-infrared (775 nm), ultrashort (∼100 fs) circularly-polarized laser pulse is studied based on the spin-orbit coupled Heisenberg model. We find that the magnetic spin momentum undergoes an oscillation in time during the interaction with a driving laser pulse, which can be explained as a classical counterpart of the Rabi oscillation associated with a spin-orbit coupling. The optimal spin reversal is achieved by adjusting the pulse duration to one half the Rabi oscillation period. A successive spin reversal by a delayed pulse is possible if it has the opposite helicity and a shorter duration relative to the first pulse. Moreover, inclusion of an exchange interaction term in the Hamiltonian leads to a precession of the magnetic spin momentum that lasts even after the driving laser pulse turns off. This spin precession is stronger in antiferromagnets than ferrimagnets.

  1. Integrated all-optical infrared switchable plasmonic quantum cascade laser.

    PubMed

    Kohoutek, John; Bonakdar, Alireza; Gelfand, Ryan; Dey, Dibyendu; Nia, Iman Hassani; Fathipour, Vala; Memis, Omer Gokalp; Mohseni, Hooman

    2012-05-09

    We report a type of infrared switchable plasmonic quantum cascade laser, in which far field light in the midwave infrared (MWIR, 6.1 μm) is modulated by a near field interaction of light in the telecommunications wavelength (1.55 μm). To achieve this all-optical switch, we used cross-polarized bowtie antennas and a centrally located germanium nanoslab. The bowtie antenna squeezes the short wavelength light into the gap region, where the germanium is placed. The perturbation of refractive index of the germanium due to the free carrier absorption produced by short wavelength light changes the optical response of the antenna and the entire laser intensity at 6.1 μm significantly. This device shows a viable method to modulate the far field of a laser through a near field interaction.

  2. All optical labeling scheme with vestigial sideband payload.

    PubMed

    Chen, Hongwei; Chen, Minghua; Dai, Yitang; Xie, Shizhong; Zhou, Bingkun

    2005-04-04

    A novel scheme based on 40Gb/s vestigial sideband modulation for optical payload and label multiplex and separation in all optical label switching (AOLS) networks is firstly proposed and experimentally demonstrated. The payload is combined and separated with wavelength labels by optical filters. The experiment results show that after label separation, the power penalties of payload and label are both very little. The influence of the wavelength difference between label and payload is also discussed. The power penalty of payload can be less than 1dB as long as the wavelength difference is larger than 0.1nm. This scheme highly reduces the channel bandwidth of payload and label and is proposing to be used in future optical Internet.

  3. All-optical reservoir computer based on saturation of absorption.

    PubMed

    Dejonckheere, Antoine; Duport, François; Smerieri, Anteo; Fang, Li; Oudar, Jean-Louis; Haelterman, Marc; Massar, Serge

    2014-05-05

    Reservoir computing is a new bio-inspired computation paradigm. It exploits a dynamical system driven by a time-dependent input to carry out computation. For efficient information processing, only a few parameters of the reservoir needs to be tuned, which makes it a promising framework for hardware implementation. Recently, electronic, opto-electronic and all-optical experimental reservoir computers were reported. In those implementations, the nonlinear response of the reservoir is provided by active devices such as optoelectronic modulators or optical amplifiers. By contrast, we propose here the first reservoir computer based on a fully passive nonlinearity, namely the saturable absorption of a semiconductor mirror. Our experimental setup constitutes an important step towards the development of ultrafast low-consumption analog computers.

  4. Self-organized plasmonic metasurfaces for all-optical modulation

    NASA Astrophysics Data System (ADS)

    Della Valle, G.; Polli, D.; Biagioni, P.; Martella, C.; Giordano, M. C.; Finazzi, M.; Longhi, S.; Duò, L.; Cerullo, G.; Buatier de Mongeot, F.

    2015-06-01

    We experimentally demonstrate a self-organized metasurface with a polarization dependent transmittance that can be dynamically controlled by optical means. The configuration consists of tightly packed plasmonic nanowires with a large dispersion of width and height produced by the defocused ion-beam sputtering of a thin gold film supported on a silica glass. Our results are quantitatively interpreted according to a theoretical model based on the thermomodulational nonlinearity of gold and a finite-element numerical analysis of the absorption and scattering cross-sections of the nanowires. We found that the polarization sensitivity of the metasurface can be strongly enhanced by pumping with ultrashort laser pulses, leading to potential applications in ultrafast all-optical modulation and switching of light.

  5. All-optical tunable multilevel amplitude regeneration based on coherent wave mixing using a polarizer.

    PubMed

    Bakhtiari, Zahra; Sawchuk, Alexander A

    2015-04-20

    We describe and demonstrate an all-optical tunable phase- preserving scheme for multilevel amplitude regeneration based on coherent optical wave mixing using a polarizer for optical star 8-quadrature-amplitude modulation (star-8QAM) and star-16QAM signals with a power ratio of 1:5. Amplitude noise can be efficiently suppressed on both amplitude levels. A regeneration factor of nearly 5 for the higher-amplitude level of star-8QAM and 3 for lower-amplitude level are achieved. The system robustness against nonlinear phase noise originating from the Gordon-Mollenauer effect in a 150 km transmission line is investigated using the proposed amplitude regenerator.

  6. Dual correlated pumping scheme for phase noise preservation in all-optical wavelength conversion.

    PubMed

    Anthur, Aravind P; Watts, Regan T; Shi, Kai; Carroll, John O'; Venkitesh, Deepa; Barry, Liam P

    2013-07-01

    We study the effect of transfer of phase noise in different four wave mixing schemes using a coherent phase noise measurement technique. The nature of phase noise transfer from the pump to the generated wavelengths is shown to be independent of the type of phase noise (1 / f or white noise frequency components). We then propose a novel scheme using dual correlated pumps to prevent the increase in phase noise in the conjugate wavelengths. The proposed scheme is experimentally verified by the all-optical wavelength conversion of a DQPSK signal at 10.7 GBaud.

  7. All optical space-to-time mapping using modal dispersion of multimode fiber

    NASA Astrophysics Data System (ADS)

    Tan, Zhongwei; Sun, Jian; Li, Ying; Ren, Wenhua; Li, Tangjun

    2017-04-01

    We experimentally demonstrate an all optical space-to-time mapping process using modal dispersion of large core high numerical aperture step-index multimode fiber in this paper. We use light beam with different input angle to excite various modes in a span of multimode fiber. The input optical pulses are stretched in time by modal dispersion and received by a large area, high speed photodiode. Through this process, the spatial information is directly mapped into device's temporal response. It has high speed, broad bandwidth and low system latency. Comparing with the widely used spectral imaging technology, this device is weak dependent of the input signal wavelength and optical carrier bandwidth.

  8. Two all-optical logic gates in a single photonic interferometer

    NASA Astrophysics Data System (ADS)

    Araújo, Antônio; Oliveira, Antônio; Martins, Francisco; Coelho, Amarílio; Fraga, Wilton; Nascimento, José

    2015-11-01

    In this paper is presented the all-optical AND and OR gates with high contrast ratio in a single interferometric configuration, i.e., when two logic signals are modulated in the input of the interferometer, so we have the OR gate in the first output and the AND gate in the second output. These logic gates were obtained by numerical investigation of the Mach-Zehnder interferometer constituted of dual-core nonlinear photonic crystal fiber operating with ultrashort fundamental solitons of 100 fs. To represent the logic information, pulse amplitude modulation by amplitude shift-keying was used.

  9. Ultrafast defect dynamics: A new approach to all optical broadband switching employing amorphous selenium thin films

    SciTech Connect

    Sharma, Rituraj; Adarsh, K. V. E-mail: adarsh@iiserb.ac.in; Prasai, Kiran; Drabold, D. A. E-mail: adarsh@iiserb.ac.in

    2015-07-15

    Optical switches offer higher switching speeds than electronics, however, in most cases utilizing the interband transitions of the active medium for switching. As a result, the signal suffers heavy losses. In this article, we demonstrate a simple and yet efficient ultrafast broadband all-optical switching on ps timescale in the sub-bandgap region of the a-Se thin film, where the intrinsic absorption is very weak. The optical switching is attributed to short-lived transient defects that form localized states in the bandgap and possess a large electron-phonon coupling. We model these processes through first principles simulation that are in agreement with the experiments.

  10. Design challenges of EO polymer based leaky waveguide deflector for 40 Gs/s all-optical analog-to-digital converters

    NASA Astrophysics Data System (ADS)

    Hadjloum, Massinissa; El Gibari, Mohammed; Li, Hongwu; Daryoush, Afshin S.

    2016-08-01

    Design challenges and performance optimization of an all-optical analog-to-digital converter (AOADC) is presented here. The paper addresses both microwave and optical design of a leaky waveguide optical deflector using electro-optic (E-O) polymer. The optical deflector converts magnitude variation of the applied RF voltage into variation of deflection angle out of a leaky waveguide optical beam using the linear E-O effect (Pockels effect) as part of the E-O polymer based optical waveguide. This variation of deflection angle as result of the applied RF signal is then quantized using optical windows followed by an array of high-speed photodetectors. We optimized the leakage coefficient of the leaky waveguide and its physical length to achieve the best trade-off between bandwidth and the deflected optical beam resolution, by improving the phase velocity matching between lightwave and microwave on one hand and using pre-emphasis technique to compensate for the RF signal attenuation on the other hand. In addition, for ease of access from both optical and RF perspective, a via-hole less broad bandwidth transition is designed between coplanar pads and coupled microstrip (CPW-CMS) driving electrodes. With the best reported E-O coefficient of 350 pm/V, the designed E-O deflector should allow an AOADC operating over 44 giga-samples-per-seconds with an estimated effective resolution of 6.5 bits on RF signals with Nyquist bandwidth of 22 GHz. The overall DC power consumption of all components used in this AOADC is of order of 4 W and is dominated by power consumption in the power amplifier to generate a 20 V RF voltage in 50 Ohm system. A higher sampling rate can be achieved at similar bits of resolution by interleaving a number of this elementary AOADC at the expense of a higher power consumption.

  11. Titan's Sand Seas properties from the modelling of microwave-backscattered signal of Cassini/SAR

    NASA Astrophysics Data System (ADS)

    Lucas, Antoine; Rodriguez, Sébastien; Lommonier, Florentin; Ferrari, Cécile; Paillou, Philippe; Le Gall, Alice; Narteau, Clément

    2016-04-01

    Titan's sand seas may reflect the current and past surface conditions. Assessing the physicochemical properties and the morphodynamics of the equatorial linear dunes is a milestone in our comprehension of the climatic and geological history of the largest Saturn's moon. Based on enhanced SAR processing leading to despeckled Cassini RADAR data sets, we analyzed quantitatively the surface properties (e.g., slopes, texture, composition...) over the sand seas. First, using a large amount of overlaps and a wide range of incidence angle and azimuths, we show that the radar cross-section over the inter-dunes strongly differs from the one over the dunes. This strongly suggests significant difference in the physical properties between these two geomorphic units. Then, we derived quantitatively the surface properties from the modelling of microwave-backscattered signal using a Monte-Carlo inversion. Our results show that dunes are globally more microwaves absorbent than the inter-dunes. The inter-dunes are smoother with a higher dielectric constant than the dunes. Considering the composition, the inter-dunes are in between the dunes and the bright inselbergs mainly composed of water ice, suggesting the presence of a shallow layer of sediment in between the dunes. This may suggest that Titan dunes are developing over a coarser sediment bed similarly to what is observed in some terrestrial sand seas such as in Ténéré desert (Niger, see also contribution #EGU2016-13383). Additionally, potential secondary bedforms (such as ripples) as well as avalanche faces may have been detected.

  12. The application of distributed Raman amplification in an all optical network

    NASA Astrophysics Data System (ADS)

    Zheng, Xiaoping; Feng, Feifei; Zhang, Hanyi; Li, Yanhe

    2003-04-01

    The effect of distributed Raman amplification (DRA) on the optical signal to noise ratio (OSNR) of an all optical network (AON) is examined by analyzing two types of node isolated principal (NIP). Based on the parameters used in calculation, it is found that in the first case of NIP, the OSNR of a signal passing through such AON can be improved by about 8 dB compared with no DRA. Whereas in the second case of NIP, the OSNR of the signal can be reduced by 11 dB. This kind of phenomena is analyzed and attributed to the dependence of noise figure of amplification system on the way of the active amplification utilization.

  13. Efficient all-optical switch using a {Lambda} atom in a cavity QED system

    SciTech Connect

    Nielsen, Anne E. B.; Kerckhoff, Joseph

    2011-10-15

    We propose an all-optical switch constructed from a two-mode optical resonator containing a strongly coupled, three-state system. The coupling allows a weak, continuous wave laser drive to incoherently control the transmission of a much stronger, continuous wave signal laser into (and through) the resonator. We demonstrate that in this simple setup the presence of a control drive with 1/10th the power of the signal drive can induce near complete reflection of the signal, while its absence allows for near complete transmission. The switch can also be operated as a set-reset relay with two control inputs that efficiently drive the switch into either the reflecting or the transmitting state.

  14. Burst switching without guard interval in all-optical software-define star intra-data center network

    NASA Astrophysics Data System (ADS)

    Ji, Philip N.; Wang, Ting

    2014-02-01

    Optical switching has been introduced in intra-data center networks (DCNs) to increase capacity and to reduce power consumption. Recently we proposed a star MIMO OFDM-based all-optical DCN with burst switching and software-defined networking. Here, we introduce the control procedure for the star DCN in detail for the first time. The timing, signaling, and operation are described for each step to achieve efficient bandwidth resource utilization. Furthermore, the guidelines for the burst assembling period selection that allows burst switching without guard interval are discussed. The star all-optical DCN offers flexible and efficient control for next-generation data center application.

  15. Ultracompact 160 Gbaud all-optical demultiplexing exploiting slow light in an engineered silicon photonic crystal waveguide.

    PubMed

    Corcoran, Bill; Pelusi, Mark D; Monat, Christelle; Li, Juntao; O'Faolain, Liam; Krauss, Thomas F; Eggleton, Benjamin J

    2011-05-01

    We demonstrate all-optical demultiplexing of a high-bandwidth, time-division multiplexed 160 Gbit/s signal to 10 Gbit/s channels, exploiting slow light enhanced four-wave mixing in a dispersion engineered, 96 μm long planar photonic crystal waveguide. We report error-free (bit error rate<10⁻⁹) operation of all 16 demultiplexed channels, with a power penalty of 2.2-2.4 dB, highlighting the potential of these structures as a platform for ultracompact all-optical nonlinear processes.

  16. All-optical transistors and logic gates using a parity-time-symmetric Y-junction: Design and simulation

    SciTech Connect

    Ding, Shulin; Wang, Guo Ping

    2015-09-28

    Classical nonlinear or quantum all-optical transistors are dependent on the value of input signal intensity or need extra co-propagating beams. In this paper, we present a kind of all-optical transistors constructed with parity-time (PT)-symmetric Y-junctions, which perform independently on the value of signal intensity in an unsaturated gain case and can also work after introducing saturated gain. Further, we show that control signal can switch the device from amplification of peaks in time to transformation of peaks to amplified troughs. By using these PT-symmetric Y-junctions with currently available materials and technologies, we can implement interesting logic functions such as NOT and XOR (exclusive OR) gates, implying potential applications of such structures in designing optical logic gates, optical switches, and signal transformations or amplifications.

  17. All-optical regulation of gene expression in targeted cells

    NASA Astrophysics Data System (ADS)

    Wang, Yisen; He, Hao; Li, Shiyang; Liu, Dayong; Lan, Bei; Hu, Minglie; Cao, Youjia; Wang, Chingyue

    2014-06-01

    Controllable gene expression is always a challenge and of great significance to biomedical research and clinical applications. Recently, various approaches based on extra-engineered light-sensitive proteins have been developed to provide optogenetic actuators for gene expression. Complicated biomedical techniques including exogenous genes engineering, transfection, and material delivery are needed. Here we present an all-optical method to regulate gene expression in targeted cells. Intrinsic or exogenous genes can be activated by a Ca2+-sensitive transcription factor nuclear factor of activated T cells (NFAT) driven by a short flash of femtosecond-laser irradiation. When applied to mesenchymal stem cells, expression of a differentiation regulator Osterix can be activated by this method to potentially induce differentiation of them. A laser-induced ``Ca2+-comb'' (LiCCo) by multi-time laser exposure is further developed to enhance gene expression efficiency. This noninvasive method hence provides an encouraging advance of gene expression regulation, with promising potential of applying in cell biology and stem-cell science.

  18. Recoil-induced Resonances as All-optical Switches

    NASA Astrophysics Data System (ADS)

    Narducci, F. A.; Desavage, S. A.; Gordon, K. H.; Duncan, D. L.; Welch, G. R.; Davis, J. P.

    2010-03-01

    We have measured recoil-induced resonances (RIR) [1,2] in our system of laser-cooled 85Rb atoms. Although this technique has been demonstrated to be useful for the purpose of extracting the cloud temperature [3], our aim was to demonstrate an all optical switch based on recoil-induced resonances. In addition to a very narrow ``free-space'' recoil-induced resonance of approximately 15 kHz, we also discovered a much broader resonance (˜30 MHz), caused by standing waves established by our trapping fields. We compare and contrast the switching dynamics of these two resonances and demonstrate optical switching using both resonances. Finally, we consider the applicability of the narrow, free-space resonance to the slowing of a weak probe field. [1] J. Guo, P.R. Berman, B. Dubetsky and G. Grynberg PRA, 46, 1426 (1992). [2] (a) P. Verkerk, B. Loumis, C. Salomon, C. Cohen-Tannoudji, J. Courtois PRL, 68, 3861 (1992). (b) G. Grynberg, J-Y Courtois, B. Lounis, P. Verkerk PRL, 72, 3017 (1994). [3] (a) T. Brzozowski, M. Brzozowska, J. Zachorowski, M. Zawada, W. Gawlik PRA, 71, 013401 (2005). (b) M. Brzozowska, T. Brzozowski J. Zachorowski, W. Gawlik PRA, 72, 061401(R), (2005).

  19. All-optical three-dimensional electron pulse compression

    NASA Astrophysics Data System (ADS)

    Jie Wong, Liang; Freelon, Byron; Rohwer, Timm; Gedik, Nuh; Johnson, Steven G.

    2015-01-01

    We propose an all-optical, three-dimensional electron pulse compression scheme in which Hermite-Gaussian optical modes are used to fashion a three-dimensional optical trap in the electron pulse’s rest frame. We show that the correct choices of optical incidence angles are necessary for optimal compression. We obtain analytical expressions for the net impulse imparted by Hermite-Gaussian free-space modes of arbitrary order. Although we focus on electrons, our theory applies to any charged particle and any particle with non-zero polarizability in the Rayleigh regime. We verify our theory numerically using exact solutions to Maxwell’s equations for first-order Hermite-Gaussian beams, demonstrating single-electron pulse compression factors of \\gt {{10}2} in both longitudinal and transverse dimensions with experimentally realizable optical pulses. The proposed scheme is useful in ultrafast electron imaging for both single- and multi-electron pulse compression, and as a means of circumventing temporal distortions in magnetic lenses when focusing ultrashort electron pulses. Other applications include the creation of flat electron beams and ultrashort electron bunches for coherent terahertz emission.

  20. All-optical broadband ultrasonography of single cells

    PubMed Central

    Dehoux, T.; Ghanem, M. Abi; Zouani, O. F.; Rampnoux, J.-M.; Guillet, Y.; Dilhaire, S.; Durrieu, M.-C.; Audoin, B.

    2015-01-01

    Cell mechanics play a key role in several fundamental biological processes, such as migration, proliferation, differentiation and tissue morphogenesis. In addition, many diseased conditions of the cell are correlated with altered cell mechanics, as in the case of cancer progression. For this there is much interest in methods that can map mechanical properties with a sub-cell resolution. Here, we demonstrate an inverted pulsed opto-acoustic microscope (iPOM) that operates in the 10 to 100 GHz range. These frequencies allow mapping quantitatively cell structures as thin as 10 nm and resolving the fibrillar details of cells. Using this non-invasive all-optical system, we produce high-resolution images based on mechanical properties as the contrast mechanisms, and we can observe the stiffness and adhesion of single migrating stem cells. The technique should allow transferring the diagnostic and imaging abilities of ultrasonic imaging to the single-cell scale, thus opening new avenues for cell biology and biomaterial sciences. PMID:25731090

  1. High-resolution all-optical photoacoustic imaging system for remote interrogation of biological specimens

    NASA Astrophysics Data System (ADS)

    Sampathkumar, Ashwin

    2014-05-01

    Conventional photoacoustic imaging (PAI) employs light pulses to produce a photoacoustic (PA) effect and detects the resulting acoustic waves using an ultrasound transducer acoustically coupled to the target tissue. The resolution of conventional PAI is limited by the sensitivity and bandwidth of the ultrasound transducer. We have developed an all-optical versatile PAI system for characterizing ex vivo and in vivo biological specimens. The system employs noncontact interferometric detection of the acoustic signals that overcomes limitations of conventional PAI. A 532-nm pump laser with a pulse duration of 5 ns excited the PA effect in tissue. Resulting acoustic waves produced surface displacements that were sensed using a 532-nm continuous-wave (CW) probe laser in a Michelson interferometer with a GHz bandwidth. The pump and probe beams were coaxially focused using a 50X objective giving a diffraction-limited spot size of 0.48 μm. The phase-encoded probe beam was demodulated using a homodyne interferometer. The detected time-domain signal was time reversed using k-space wave-propagation methods to produce a spatial distribution of PA sources in the target tissue. Performance was assessed using PA images of ex vivo rabbit lymph node specimens and human tooth samples. A minimum peak surface displacement sensitivity of 0.19 pm was measured. The all-optical PAI (AOPAI) system is well suited for assessment of retinal diseases, caries lesion detection, skin burns, section less histology and pressure or friction ulcers.

  2. Photonic subsampling analog-to-digital conversion of microwave signals at 40-GHz with higher than 7-ENOB resolution.

    PubMed

    Kim, Jungwon; Park, Matthew J; Perrott, Michael H; Kärtner, Franz X

    2008-10-13

    Conversion of analog signals into digital signals is one of the most important functionalities in modern signal processing systems. As the signal frequency increases beyond 10 GHz, the timing jitter from electronic clocks, currently limited at approximately 100 fs, compromises the achievable resolution of analog-to-digital converters (ADCs). Owing to their ultralow timing jitter, the use of optical pulse trains from passively mode-locked lasers has been considered to be a promising way for sampling electronic signals. In this paper, based on sub-10 fs jitter optical sampling pulse trains, we demonstrate a photonic subsampling ADC that downconverts and digitizes a narrowband microwave signal at 40 GHz carrier frequency with higher than 7 effective-number-of-bit (ENOB) resolution.

  3. All-optical relative intensity noise suppression method for the high precision fiber optic gyroscope

    NASA Astrophysics Data System (ADS)

    Zheng, Yue; Zhang, Chunxi; Li, Lijing; Song, Lailiang; Zhang, Yuhui

    2016-10-01

    The relative intensity noise (RIN) is a main factor that limits the detection accuracy of the high precision fiber optic gyroscope (FOG). The RIN spectrum is determined by the normalized autocorrelation of the optical spectrum of the broadband source and is intrinsically different from other fundamental noises. In this paper, we propose an all-optical technique to suppress the RIN. With the power addition of the optical waves from the signal optical path and the reference optical path, the RIN is effectively eliminated at the eigen frequency of the FOG, which is also the demodulation window for the rotation rate signal. Compared with the traditional optical configuration of the FOG, there is only one additional optical component. Experimental results show that, with this method, we can achieve a nearly 3-fold improvement in the angular random walk coefficient. The improved optical configuration for RIN suppression is simple to realize and suitable for engineering application.

  4. Vortex-based all-optical manipulation of stored light at low light levels.

    PubMed

    Zhao, Lu

    2015-11-16

    We exploit the giant cross-Kerr nonlinearity of electromagnetically induced transparency (EIT) system in ultracold atoms to implement vortex-based multimode manipulation of stored light at low light levels. Using image-bearing signal light fields with angular intensity profiles, sinusoidal grating structures with phase-only modulation can be azimuthally imprinted on the stored probe light field, where the nonlinear absorption loss can be ignored. Upon retrieval of the probe light, collinearly superimposed vortex modes can be generated in the far field. Considering the finite size of atomic gas, the Fraunhofer diffraction patterns of the retrieved probe fields and their spiral spectra are numerically investigated, where the diffracted vortex modes can be efficiently controlled by tuning the weak signal fields. Our studies not only exhibit a fundamental diffraction phenomenon with angular grating structures in EIT system, but also provide a fascinating opportunity to realize multidimensional quantum information processing for stored light in an all-optical manner.

  5. Design and analysis of an all optical OR gate using surface plasmon hopping along metallic nanorods

    NASA Astrophysics Data System (ADS)

    Pourali, Elyar; Asadolahi Baboli, Mohadeseh

    2015-04-01

    This paper proposes a novel design technique for realization of plasmonic logic gates. A 2D plasmonic all optical OR gate with the miniaturized size of 5 μm × 3 μm is presented. Ag metallic reflectors form the input and output waveguides to confine the light inside the gate. The logic operations are realized through selective propagation of light in the gate through hopping of the surface plasmon resonances along the metallic nanorods. With this novel idea approximately 100% of input signal propagates through the output waveguide and no division occurs at the cross point. Due to its simplicity, the OR gate was chosen to be the first implemented logic gate to verify the performance of the proposed method. Our proposed optical gate works at the operating wavelength of 652 nm with input signals of a transverse magnetic (TM) (Hz, Ex, Ey) polarized continuous wave with near zero cross talk between two input waveguides.

  6. Noise figure of microwave photonic links operating under large-signal modulation and its application to optoelectronic oscillators.

    PubMed

    Hosseini, Seyyed Esmail; Banai, Ali

    2014-10-01

    The noise performance of intensity-modulation direct-detection microwave photonic links (MWPL) operating under large-signal conditions has been studied in this paper. A sinusoidal signal plus narrowband white Gaussian noise is applied at the radio frequency input of the link, and the output spectrum is derived using a nonlinear analytical approach. We show that the output SNR can be severely affected by the interaction of signal and noise due to the nonlinearity of the MWPL combined with the large input modulating signal. It is shown that the large-signal noise figure (NF) of an MWPL depends on the input power, a dependence that is not readily apparent under small-signal conditions, due to two unavoidable issues appearing in the large-signal conditions: (1) the link power gain is a function of its input power, and (2) the link power gain is not the same for the signal and noise due to the capture effect. We also have observed that if shot noise or laser relative intensity noise (RIN) is the dominant source of noise, link large-signal NF increases as the input signal power increases. We have shown that, when the MWPL is operating in the linear regime, our theoretical predictions approach the already published results on small-signal NF, which are verified by experimental data. We have shown that large-signal NF affects the noise performance of optoelectronic oscillators because they contain MWPLs at saturation.

  7. All-Optical Ultrasound Transducers for High Resolution Imaging

    NASA Astrophysics Data System (ADS)

    Sheaff, Clay Smith

    High frequency ultrasound (HFUS) has increasingly been used within the past few decades to provide high resolution (< 200 mum) imaging in medical applications such as endoluminal imaging, intravascular imaging, ophthalmology, and dermatology. The optical detection and generation of HFUS using thin films offers numerous advantages over traditional piezoelectric technology. Circumvention of an electronic interface with the device head is one of the most significant given the RF noise, crosstalk, and reduced capacitance that encumbers small-scale electronic transducers. Thin film Fabry-Perot interferometers - also known as etalons - are well suited for HFUS receivers on account of their high sensitivity, wide bandwidth, and ease of fabrication. In addition, thin films can be used to generate HFUS when irradiated with optical pulses - a method referred to as Thermoelastic Ultrasound Generation (TUG). By integrating a polyimide (PI) film for TUG into an etalon receiver, we have created for the first time an all-optical ultrasound transducer that is both thermally stable and capable of forming fully sampled 2-D imaging arrays of arbitrary configuration. Here we report (1) the design and fabrication of PI-etalon transducers; (2) an evaluation of their optical and acoustic performance parameters; (3) the ability to conduct high-resolution imaging with synthetic 2-D arrays of PI-etalon elements; and (4) work towards a fiber optic PI-etalon for in vivo use. Successful development of a fiber optic imager would provide a unique field-of-view thereby exposing an abundance of prospects for minimally-invasive analysis, diagnosis, and treatment of disease.

  8. All-optical image processing with nonlinear liquid crystals

    NASA Astrophysics Data System (ADS)

    Hong, Kuan-Lun

    Liquid crystals are fascinating materials because of several advantages such as large optical birefringence, dielectric anisotropic, and easily compatible to most kinds of materials. Compared to the electro-optical properties of liquid crystals widely applied in displays and switching application, transparency through most parts of wavelengths also makes liquid crystals a better candidate for all-optical processing. The fast response time of liquid crystals resulting from multiple nonlinear effects, such as thermal and density effect can even make real-time processing realized. In addition, blue phase liquid crystals with spontaneously self-assembled three dimensional cubic structures attracted academic attention. In my dissertation, I will divide the whole contents into six parts. In Chapter 1, a brief introduction of liquid crystals is presented, including the current progress and the classification of liquid crystals. Anisotropy and laser induced director axis reorientation is presented in Chapter 2. In Chapter 3, I will solve the electrostrictive coupled equation and analyze the laser induced thermal and density effect in both static and dynamic ways. Furthermore, a dynamic simulation of laser induced density fluctuation is proposed by applying finite element method. In Chapter 4, two image processing setups are presented. One is the intensity inversion experiment in which intensity dependent phase modulation is the mechanism. The other is the wavelength conversion experiment in which I can read the invisible image with a visible probe beam. Both experiments are accompanied with simulations to realize the matching between the theories and practical experiment results. In Chapter 5, optical properties of blue phase liquid crystals will be introduced and discussed. The results of grating diffractions and thermal refractive index gradient are presented in this chapter. In addition, fiber arrays imaging and switching with BPLCs will be included in this chapter

  9. Tangled nonlinear driven chain reactions of all optical singularities

    NASA Astrophysics Data System (ADS)

    Vasil'ev, V. I.; Soskin, M. S.

    2012-03-01

    Dynamics of polarization optical singularities chain reactions in generic elliptically polarized speckle fields created in photorefractive crystal LiNbO3 was investigated in details Induced speckle field develops in the tens of minutes scale due to photorefractive 'optical damage effect' induced by incident beam of He-Ne laser. It was shown that polarization singularities develop through topological chain reactions of developing speckle fields driven by photorefractive nonlinearities induced by incident laser beam. All optical singularities (C points, optical vortices, optical diabolos,) are defined by instantaneous topological structure of the output wavefront and are tangled by singular optics lows. Therefore, they have develop in tangled way by six topological chain reactions driven by nonlinear processes in used nonlinear medium (photorefractive LiNbO3:Fe in our case): C-points and optical diabolos for right (left) polarized components domains with orthogonally left (right) polarized optical vortices underlying them. All elements of chain reactions consist from loop and chain links when nucleated singularities annihilated directly or with alien singularities in 1:9 ratio. The topological reason of statistics was established by low probability of far enough separation of born singularities pair from existing neighbor singularities during loop trajectories. Topology of developing speckle field was measured and analyzed by dynamic stokes polarimetry with few seconds' resolution. The hierarchy of singularities govern scenario of tangled chain reactions was defined. The useful space-time data about peculiarities of optical damage evolution were obtained from existence and parameters of 'islands of stability' in developing speckle fields.

  10. All-optical, all-fiber circulating shift register with an inverter.

    PubMed

    Whitaker, N A; Gabriel, M C; Avramopoulos, H; Huang, A

    1991-12-15

    An all-optical fiber Sagnac interferometer switch and erbium amplifier have been combined to form an all-optical 254-bit circulating shift register with an inverter. This simple optical loop memory demonstrates the cascadability of Sagnac interferometer switches.

  11. Photonic encryption : modeling and functional analysis of all optical logic.

    SciTech Connect

    Tang, Jason D.; Schroeppel, Richard Crabtree; Robertson, Perry J.

    2004-10-01

    With the build-out of large transport networks utilizing optical technologies, more and more capacity is being made available. Innovations in Dense Wave Division Multiplexing (DWDM) and the elimination of optical-electrical-optical conversions have brought on advances in communication speeds as we move into 10 Gigabit Ethernet and above. Of course, there is a need to encrypt data on these optical links as the data traverses public and private network backbones. Unfortunately, as the communications infrastructure becomes increasingly optical, advances in encryption (done electronically) have failed to keep up. This project examines the use of optical logic for implementing encryption in the photonic domain to achieve the requisite encryption rates. This paper documents the innovations and advances of work first detailed in 'Photonic Encryption using All Optical Logic,' [1]. A discussion of underlying concepts can be found in SAND2003-4474. In order to realize photonic encryption designs, technology developed for electrical logic circuits must be translated to the photonic regime. This paper examines S-SEED devices and how discrete logic elements can be interconnected and cascaded to form an optical circuit. Because there is no known software that can model these devices at a circuit level, the functionality of S-SEED devices in an optical circuit was modeled in PSpice. PSpice allows modeling of the macro characteristics of the devices in context of a logic element as opposed to device level computational modeling. By representing light intensity as voltage, 'black box' models are generated that accurately represent the intensity response and logic levels in both technologies. By modeling the behavior at the systems level, one can incorporate systems design tools and a simulation environment to aid in the overall functional design. Each black box model takes certain parameters (reflectance, intensity, input response), and models the optical ripple and time delay

  12. All-optical electrophysiology in mammalian neurons using engineered microbial rhodopsins

    PubMed Central

    Hochbaum, Daniel R.; Zhao, Yongxin; Farhi, Samouil L.; Klapoetke, Nathan; Werley, Christopher A.; Kapoor, Vikrant; Zou, Peng; Kralj, Joel M.; Maclaurin, Dougal; Smedemark-Margulies, Niklas; Saulnier, Jessica L.; Boulting, Gabriella L.; Straub, Christoph; Cho, Yong Ku; Melkonian, Michael; Wong, Gane Ka-Shu; Harrison, D. Jed; Murthy, Venkatesh N.; Sabatini, Bernardo; Boyden, Edward S.; Campbell, Robert E.; Cohen, Adam E.

    2014-01-01

    All-optical electrophysiology—spatially resolved simultaneous optical perturbation and measurement of membrane voltage—would open new vistas in neuroscience research. We evolved two archaerhodopsin-based voltage indicators, QuasAr1 and 2, which show improved brightness and voltage sensitivity, microsecond response times, and produce no photocurrent. We engineered a novel channelrhodopsin actuator, CheRiff, which shows improved light sensitivity and kinetics, and spectral orthogonality to the QuasArs. A co-expression vector, Optopatch, enabled crosstalk-free genetically targeted all-optical electrophysiology. In cultured neurons, we combined Optopatch with patterned optical excitation to probe back-propagating action potentials in dendritic spines, synaptic transmission, sub-cellular microsecond-timescale details of action potential propagation, and simultaneous firing of many neurons in a network. Optopatch measurements revealed homeostatic tuning of intrinsic excitability in human stem cell-derived neurons. In brain slice, Optopatch induced and reported action potentials and subthreshold events, with high signal-to-noise ratios. The Optopatch platform enables high-throughput, spatially resolved electrophysiology without use of conventional electrodes. PMID:24952910

  13. On-chip passive three-port circuit of all-optical ordered-route transmission

    PubMed Central

    Liu, Li; Dong, Jianji; Gao, Dingshan; Zheng, Aoling; Zhang, Xinliang

    2015-01-01

    On-chip photonic circuits of different specific functions are highly desirable and becoming significant demands in all-optical communication network. Especially, the function to control the transmission directions of the optical signals in integrated circuits is a fundamental research. Previous schemes, such as on-chip optical circulators, are mostly realized by Faraday effect which suffers from material incompatibilities between semiconductors and magneto-optical materials. Achieving highly functional circuits in which light circulates in a particular direction with satisfied performances are still difficult in pure silicon photonics platform. Here, we propose and experimentally demonstrate a three-port passive device supporting optical ordered-route transmission based on silicon thermo-optic effect for the first time. By injecting strong power from only one port, the light could transmit through the three ports in a strict order (1→2, 2→3, 3→1) while be blocked in the opposite order (1→3, 3→2, 2→1). The blocking extinction ratios and operation bandwidths have been investigated in this paper. Moreover, with compact size, economic fabrication process and great extensibility, this proposed photonic integrated circuit is competitive to be applied in on-chip all-optical information processing systems, such as path priority selector. PMID:25970855

  14. All-optical logic gates based on cross-phase modulation in an asymmetric coupler

    NASA Astrophysics Data System (ADS)

    Li, Qiliang; Yuan, Hongliang

    2014-05-01

    In this paper we propose an operation of an all-optical logical gate based on an asymmetric nonlinear directional coupler operating with the cross-phase modulation. Two-input OR and XOR gates and a new logical operation based on an asymmetric nonlinear directional coupler, which can be applied to transmission and processing of signals in all-optical systems, are examined. Initially, we evaluate the effect of the pump power on switching. We import a pulse into the nonlinear directional coupler, meanwhile adding a pump light via wavelength division multiplex in order to take advantage of Kerr effect and produce the cross-phase modulation. In this situation, we analyze two possible situations for the two-input logical gate, and draw a switching characteristic curve via Matlab. Finally, we define the truth table and it is clear that OR and XOR logic gates and a new logical operation can be realized by changing the pump power. Next the investigation also indicates that to change the input pulse's phase switching can be realized. In the same way, we define the truth table and it can be observed that different logic gates are realized.

  15. Design of an All-Optical Network Based on LCoS Technologies

    NASA Astrophysics Data System (ADS)

    Cheng, Yuh-Jiuh; Shiau, Yhi

    2016-06-01

    In this paper, an all-optical network composed of the ROADMs (reconfigurable optical add-drop multiplexer), L2/L3 optical packet switches, and the fiber optical cross-connection for fiber scheduling and measurement based on LCoS (liquid crystal on silicon) technologies is proposed. The L2/L3 optical packet switches are designed with optical output buffers. Only the header of optical packets is converted to electronic signals to control the wavelength of input ports and the packet payloads can be transparently destined to their output ports. An optical output buffer is designed to queue the packets when more than one incoming packet should reach to the same destination output port. For preserving service-packet sequencing and fairness of routing sequence, a priority scheme and a round-robin algorithm are adopted at the optical output buffer. The wavelength of input ports is designed for routing incoming packets using LCoS technologies. Finally, the proposed OFS (optical flow switch) with input buffers can quickly transfer the big data to the output ports and the main purpose of the OFS is to reduce the number of wavelength reflections. The all-optical content delivery network is comprised of the OFSs for a large amount of audio and video data transmissions in the future.

  16. Integrated all-optical logic and arithmetic operations with the help of a TOAD-based interferometer device--alternative approach.

    PubMed

    Roy, Jitendra Nath; Gayen, Dilip Kumar

    2007-08-01

    Interferometric devices have drawn a great interest in all-optical signal processing for their high-speed photonic activity. The nonlinear optical loop mirror provides a major support to optical switching based all-optical logic and algebraic operations. The gate based on the terahertz optical asymmetric demultiplexer (TOAD) has added new momentum in this field. Optical tree architecture (OTA) plays a significant role in the optical interconnecting network. We have tried to exploit the advantages of both OTA- and TOAD-based switches. We have proposed a TOAD-based tree architecture, a new and alternative scheme, for integrated all-optical logic and arithmetic operations.

  17. Integrated all-optical logic and arithmetic operations with the help of a TOAD-based interferometer device--alternative approach

    NASA Astrophysics Data System (ADS)

    Nath Roy, Jitendra; Gayen, Dilip Kumar

    2007-08-01

    Interferometric devices have drawn a great interest in all-optical signal processing for their high-speed photonic activity. The nonlinear optical loop mirror provides a major support to optical switching based all-optical logic and algebraic operations. The gate based on the terahertz optical asymmetric demultiplexer (TOAD) has added new momentum in this field. Optical tree architecture (OTA) plays a significant role in the optical interconnecting network. We have tried to exploit the advantages of both OTA- and TOAD-based switches. We have proposed a TOAD-based tree architecture, a new and alternative scheme, for integrated all-optical logic and arithmetic operations.

  18. PROBING THE DARK FLOW SIGNAL IN WMAP 9 -YEAR AND PLANCK COSMIC MICROWAVE BACKGROUND MAPS

    SciTech Connect

    Atrio-Barandela, F.; Kashlinsky, A.; Ebeling, H.; Fixsen, D. J.; Kocevski, D. E-mail: Alexander.Kashlinsky@nasa.gov E-mail: Dale.Fixsen@nasa.gov

    2015-09-10

    The “dark flow” dipole is a statistically significant dipole found at the position of galaxy clusters in filtered maps of Cosmic Microwave Background (CMB) temperature anisotropies. The dipole measured in WMAP 3-, 5-, and 7- year data releases was (1) mutually consistent, (2) roughly aligned with the all-sky CMB dipole, and (3) correlated with clusters’ X-ray luminosities. We analyzed WMAP 9 -year and Planck 1st- year data releases using a catalog of 980 clusters outside of the Kp0 mask to test our earlier findings. The dipoles measured on these new data sets are fully compatible with our earlier estimates, are similar in amplitude and direction to our previous results, and are in disagreement with the results of an earlier study by the Planck Collaboration. Furthermore, in the Planck data sets dipoles are found to be independent of frequency, ruling out the thermal Sunyaev–Zeldovich as the source of the effect. In the data of both WMAP and Planck we find a clear correlation between the dipole measured at the cluster location in filtered maps and the average anisotropy on the original maps, further proving that the dipole is associated with clusters. The dipole signal is dominated by the most massive clusters, with a statistical significance that is better than 99%, slightly larger than in WMAP. Since both data sets differ in foreground contributions, instrumental noise, and other systematics, the agreement between the WMAP and Planck dipoles argues against them being due to systematic effects in either of the experiments.

  19. All-optical switching in silicon-on-insulator photonic wire nano-cavities.

    PubMed

    Belotti, Michele; Galli, Matteo; Gerace, Dario; Andreani, Lucio Claudio; Guizzetti, Giorgio; Md Zain, Ahmad R; Johnson, Nigel P; Sorel, Marc; De La Rue, Richard M

    2010-01-18

    We report on experimental demonstration of all-optical switching in a silicon-on-insulator photonic wire nanocavity operating at telecom wavelengths. The switching is performed with a control pulse energy as low as approximately 0.1 pJ on a cavity device that presents very high signal transmission, an ultra-high quality-factor, almost diffraction-limited modal volume and a footprint of only 5 microm(2). High-speed modulation of the cavity mode is achieved by means of optical injection of free carriers using a nanosecond pulsed laser. Experimental results are interpreted by means of finite-difference time-domain simulations. The possibility of using this device as a logic gate is also demonstrated.

  20. All-optical hash code generation and verification for low latency communications.

    PubMed

    Paquot, Yvan; Schröder, Jochen; Pelusi, Mark D; Eggleton, Benjamin J

    2013-10-07

    We introduce an all-optical, format transparent hash code generator and a hash comparator for data packets verification with low latency at high baudrate. The device is reconfigurable and able to generate hash codes based on arbitrary functions and perform the comparison directly in the optical domain. Hash codes are calculated with custom interferometric circuits implemented with a Fourier domain optical processor. A novel nonlinear scheme featuring multiple four-wave mixing processes in a single waveguide is implemented for simultaneous phase and amplitude comparison of the hash codes before and after transmission. We demonstrate the technique with single polarisation BPSK and QPSK signals up to a data rate of 80 Gb/s.

  1. All-optical generation of DFT-S-OFDM superchannels using periodic sinc pulses.

    PubMed

    Lowery, Arthur James; Zhu, Chen; Viterbo, Emanuele; Corcoran, Bill

    2014-11-03

    Discrete-Fourier-transform spread (DFT-S) optical Orthogonal Frequency Division Multiplexed (OFDM) signals offer improved nonlinearity performance in long haul optical communications systems, and can be used to form superchannels. In this paper we propose how DFT-S-OFDM superchannels can be generated and demultiplexed using all-optical techniques, and demonstrate the feasibility using numerical simulations. We also discuss how each wavelength channel is similar to recently proposed Orthogonally Time-Division Multiplexed (OrthTDM) systems using periodic-sinc pulses from, for example, a Nyquist laser. The key difference between OrthTDM and DFT-S-OFDM is the synchronization of the symbol boundaries of every modulation tributary; because of this we show that OrthTDM cannot be formed into superchannels that can be demultiplexed without penalties, but DFT-S-OFDM can be.

  2. Banded all-optical OFDM super-channels with low-bandwidth receivers.

    PubMed

    Song, Binhuang; Zhu, Chen; Corcoran, Bill; Zhuang, Leimeng; Lowery, Arthur James

    2016-08-08

    We propose a banded all-optical orthogonal frequency division multiplexing (AO-OFDM) transmission system based on synthesising a number of truncated sinc-shaped subcarriers for each sub-band. This approach enables sub-band by sub-band reception and therefore each receiver's electrical bandwidth can be significantly reduced compared with a conventional AO-OFDM system. As a proof-of-concept experiment, we synthesise 6 × 10-Gbaud subcarriers in both conventional and banded AO-OFDM systems. With a limited receiver electrical bandwidth, the experimental banded AO-OFDM system shows 2-dB optical signal to noise ratio (OSNR) benefit over conventional AO-OFDM at the 7%-overhead forward error correction (FEC) threshold. After transmission over 800-km of single-mode fiber, ≈3-dB improvement in Q-factor can be achieved at the optimal launch power at a cost of increasing the spectral width by 14%.

  3. All-optically integrated multimodality imaging system: combined photoacoustic microscopy, optical coherence tomography, and fluorescence imaging

    NASA Astrophysics Data System (ADS)

    Chen, Zhongjiang; Yang, Sihua; Xing, Da

    2016-10-01

    We have developed a multimodality imaging system by optically integrating all-optical photoacoustic microscopy (AOPAM), optical coherence tomography (OCT) and fluorescence microscopy (FLM) to provide complementary information including optical absorption, optical back-scattering and fluorescence contrast of biological tissue. By sharing the same low-coherence Michelson interferometer, AOPAM and OCT could be organically optically combined to obtain the absorption and scattering information of the biological tissues. Also, owing to using the same laser source and objective lens, intrinsically registered photoacoustic and fluorescence signals are obtained to present the radiative and nonradiative transition process of absorption. Simultaneously photoacoustic angiography, tissue structure and fluorescence molecular in vivo images of mouse ear were acquired to demonstrate the capabilities of the optically integrated trimodality imaging system, which can present more information to study tumor angiogenesis, vasculature, anatomical structure and microenvironments in vivo.

  4. Chip-integrated all-optical diode based on nonlinear plasmonic nanocavities covered with multicomponent nanocomposite

    NASA Astrophysics Data System (ADS)

    Chai, Zhen; Hu, Xiaoyong; Yang, Hong; Gong, Qihuang

    2017-01-01

    Ultracompact chip-integrated all-optical diode is realized experimentally in a plasmonic microstructure, consisting of a plasmonic waveguide side-coupled two asymmetric plasmonic composite nanocavities covered with a multicomponent nanocomposite layer, formed directly in a plasmonic circuit. Extremely large optical nonlinearity enhancement is obtained for the multicomponent nanocomposite cover layer, originating from resonant excitation, slow-light effect, and field enhancement effect. Nonreciprocal transmission was achieved based on the difference in the shift magnitude of the transparency window centers of two asymmetric plasmonic nanocavities induced by the signal light, itself, for the forward and backward propagation cases. An ultralow threshold incident light power of 145 μW (corresponding to a threshold intensity of 570 kW/cm2) is realized, which is reduced by seven orders of magnitude compared with previous reports. An ultrasmall feature size of 2 μm and a transmission contrast ratio of 15 dB are obtained simultaneously.

  5. Studies in optical parallel processing. [All optical and electro-optic approaches

    NASA Technical Reports Server (NTRS)

    Lee, S. H.

    1978-01-01

    Threshold and A/D devices for converting a gray scale image into a binary one were investigated for all-optical and opto-electronic approaches to parallel processing. Integrated optical logic circuits (IOC) and optical parallel logic devices (OPA) were studied as an approach to processing optical binary signals. In the IOC logic scheme, a single row of an optical image is coupled into the IOC substrate at a time through an array of optical fibers. Parallel processing is carried out out, on each image element of these rows, in the IOC substrate and the resulting output exits via a second array of optical fibers. The OPAL system for parallel processing which uses a Fabry-Perot interferometer for image thresholding and analog-to-digital conversion, achieves a higher degree of parallel processing than is possible with IOC.

  6. Demonstration of all-optical two bit digital comparator using self-locked Fabry-Perot laser diode

    NASA Astrophysics Data System (ADS)

    Nakarmi, Bikash; Rakib-Uddin, M.; Won, Yong Hyub

    2012-02-01

    All-optical two bit digital comparator using single mode Fabry-Perot laser diodes (SMFP-LDs) is proposed and demonstrated with 10 Gbps PRBS signal of 231-1. Digital comparators are one of the important components for decision making circuits, threshold detection, which are used in optical signal processing and optical computing. The basic principle of the comparator is based on injection locking, multi-input injection locking and combinational input injection locking (CMIL) to realize the greater than, less than, and equal to function of the basic comparator circuit. These principles are used to realize the different optical logic gates which are combined together to demonstrate optical comparator with the minimum number of components, making the configuration cheaper and simpler. The proposed method draws less current and hence power effective too. Output waveform diagram and output eye diagram for all three cases of comparator are presented to verify all functions of all-optical comparator.

  7. Novel all-optical switches based on traveling-wave semiconductor optical amplifiers

    NASA Astrophysics Data System (ADS)

    Zhu, Xiaoxing

    1997-08-01

    In this work, novel all-optical switches, which can provide both high-speed and broad-bandwidth switching simultaneously for future telecommunication networks, have been proposed and demonstrated in traveling-wave semiconductor optical amplifiers (TW-SOA). The design, fabrication and characterization of anti- reflection coating for TW-SOA were presented. Guided mode approach was used to optimize the coating conditions. High quality TW-SOA were fabricated with 21 dB small- signal gain, 0.2 dB gain ripple and 5× 10-5 residual reflectivity. The study showed careful selection of the laser wavelength was necessary in order to match the amplifier's operating wavelength. A new class of an all-optical packet switch-the wavelength recognizing switch (WRS)-was proposed. The device uses a control signal to sense the wavelength of the input data packet and taps the packet to the appropriate output port. The underlying mechanism is nearly-degenerate four-wave mixing (FWM). The implementation of the WRS in a broad-area TW-SOA provided +8.2 dB switching efficiency, -28.8 dB crosstalk and 32.9 dB signal-to-noise ratio. The switching bandwidth was 42 nm, while the recognition bandwidth was 0.03 A. Completely filter-free FWM wavelength conversion was also proposed and demonstrated for the first time. The noncollinear configuration provided 29 dB suppression of the straight-through converter beam from the converted signal. Further suppression of the strong pump beam from the converted signal was realized by using an orthogonal polarization technique, with isolation ratio of 19.2 dB achieved. A high conversion efficiency of 4.9 dB, together with a wide efficiency bandwidth of 40 nm and a large signal-to-noise ratio of 28 dB was obtained. Important material parameters were investigated for the optimization of devices' performance. Ambipolar diffusion coefficient of 8.0 cm2/s and carrier lifetime of 1.33 ns were directly measured. The diffusion coefficient decreased as the current

  8. All-Optical Micro Motors Based on Moving Gratings in Photosensitive Media

    NASA Technical Reports Server (NTRS)

    Curley, M.; Sarkisov, S. S.; Fields, A.; Smith, C.; Kukhtarev, N.; Kulishov, M. B.; Adamovsky, G. (Technical Monitor)

    2000-01-01

    An all-optical micro motor with a rotor driven by a traveling wave of surface deformation of a stator being in contact with the rotor is being studied. Instead of an ultrasonic wave produced by an electrically driven piezoelectric actuator as in ultrasonic motors, the wave is a result of a photo induced surface deformation of a photosensitive material produced by a traveling holographic grating. Two phase modulated coherent optical beams generate the grating. Several types of photosensitive materials are studied such as photorefractive crystals, photosensitive piezoelectric ceramics, and side-chain liquid crystalline polyesters. In order to be considered as a possible candidate for micro motors, the material should exhibit surface deformation produced by moving grating of the order of 10 micron. Deformations produced by static holographic gratings are studied in photorefractive crystals of LiNbO3 using high vertical resolution surface profilometer Dektak 3 and surface interferometer WYKO. An experimental set-up with moving grating has been developed. The set-up uses a two-beam interferometry configuration with one beam being reflected by a thin mirror mounted on a loud speaker. A ramp voltage signal generator drives the speaker. Changing voltage, polarity, and frequency of the signal can easily generate vibrating gratings or moving gratings in both directions. A vibrating grating has been applied to a photorefractive crystal of BSO controlled by an external electric field of the order of 104 V/cm. We have additionally studied effects of moving grating interaction with light absorbing fluids such as solutions of 2,9,16,23-Tetrakis(phenylthio)-29H, 31 Hphthalocyanine in chlorobenzene in capillary tubes. The purpose of using a liquid is to show that the moving gratings can force a liquid to shift. The interaction of a single low power focused laser beam at 633 nm with such fluid produced an intensive circular motion, which also might be applied to all-optical micro

  9. Experimental demonstration of all optical XOR and XNOR gates for differential phase modulated data

    NASA Astrophysics Data System (ADS)

    Kakarla, Ravikiran; Venkitesh, Deepa

    2014-05-01

    All optical logic gates play a key role in implementing an optically transparent network where the node functionalities are performed in the optical domain to reduce latency and power consumption. In this paper we present the experimental demonstration and details of optimization of all optical XOR/ XNOR gate using four-wave mixing (FWM) in Semiconductor Optical Amplifier (SOA) for 10 Gbps Differential Phase Shift Keyed (DPSK) data. Two DPSK modulated signals at carrier frequencies ω1 and ω2, phases ϕ1and ϕ2and a continuous wave pump at frequency ωCW and phase ϕCW are allowed to undergo FWM in a non-linear SOA to generate additional frequency components. The phase of the generated FWM idler corresponding to the frequency ω1+ ω2-ωCW given by ϕ1+ ϕ2- CW corresponds to the XOR operation in DPSK format. Light from a DFB and tunable laser source (TLS) are combined and phase-modulated using a pseudo-random bit sequence. The bit sequences in the two carrier wavelengths are separated in time by propagating through a sufficient length of SMF; the data is combined with a CW pump from a tunable laser and allowed to undergo non-degenerate FWM in a nonlinear SOA. The relative spacing between the pump and the signal wavelengths and their polarization states are optimized to yield maximum conversion efficiency in the desired idler. The XOR output is further propagated through a delay-line interferometer (DLI) to obtain XOR and XNOR outputs in the two ports of the DLI, in the OOK format. Extinction ratio and Contrast ratio of better than 7.2 dB and 10.6 dB respectively for the XNOR gate and 6.8 dB and 7.5 dB for the XOR gaterespectively.

  10. All-optical photoacoustic microscopy (AOPAM) system for remote characterization of biological tissues

    NASA Astrophysics Data System (ADS)

    Sampathkumar, Ashwin; Chitnis, Parag V.; Silverman, Ronald H.

    2014-03-01

    Conventional photoacoustic microscopy (PAM) employs light pulses to produce a photoacoustic (PA) effect and detects the resulting acoustic waves using an ultrasound transducer acoustically coupled to the target. The resolution of conventional PAM is limited by the sensitivity and bandwidth of the ultrasound transducer. We investigated a versatile, all-optical PAM (AOPAM) system for characterizing in vivo as well as ex vivo biological specimens. The system employs non-contact interferometric detection of PA signals that overcomes limitations of conventional PAM. A 532-nm pump laser with a pulse duration of 5 ns excites the PA effect in tissue. Resulting acoustic waves produce surface displacements that are sensed using a 532-nm continuous-wave (CW) probe laser in a Michelson interferometer with a 1- GHz bandwidth. The pump and probe beams are coaxially focused using a 50X objective giving a diffraction-limited spot size of 0.48 μm. The phase-encoded probe beam is demodulated using homodyne methods. The detected timedomain signal is time reversed using k-space wave-propagation methods to produce a spatial distribution of PA sources in the target tissue. A minimum surface-displacement sensitivity of 0.19 pm was measured. PA-induced surface displacements are very small; therefore, they impose stringent detection requirements and determine the feasibility of implementing an all-optical PAM in biomedical applications. 3D PA images of ex vivo porcine retina specimens were generated successfully. We believe the AOPAM system potentially is well suited for assessing retinal diseases and other near-surface biomedical applications such as sectionless histology and evaluation of skin burns and pressure or friction ulcers.

  11. All-optical NRZ wavelength conversion based on a single hybrid III-V/Si SOA and optical filtering.

    PubMed

    Wu, Yingchen; Huang, Qiangsheng; Keyvaninia, Shahram; Katumba, Andrew; Zhang, Jing; Xie, Weiqiang; Morthier, Geert; He, Jian-Jun; Roelkens, Gunther

    2016-09-05

    We demonstrate all-optical wavelength conversion (AOWC) of non-return-to-zero (NRZ) signal based on cross-gain modulation in a single heterogeneously integrated III-V-on-silicon semiconductor optical amplifier (SOA) with an optical bandpass filter. The SOA is 500 μm long and consumes less than 250 mW electrical power. We experimentally demonstrate 12.5 Gb/s and 40 Gb/s AOWC for both wavelength up and down conversion.

  12. Signal correlation in the tandem of a spin oscillator and microwave frequency discriminator with laser-pumped alkali atoms

    NASA Astrophysics Data System (ADS)

    Baranov, A. A.; Ermak, S. V.; Sagitov, E. A.; Smolin, R. V.; Semenov, V. V.

    2016-02-01

    We have studied the influence of low-frequency noise on the stability of resonance frequency of a self-oscillating magnetometer on 87Rb vapor with simultaneous monitoring of the signal of radio-optical resonance on the magnetic-field-dependent microwave transition under laser pumping at the D 2 line of the head doublet. The difference of synchronous records of detected signals reduced to the same scale in magnetic field units was processed to determine the Allan variance as a function of the averaging time. The correlation coefficient characterizing the coupling of detected signals determined by the pumping rate and intensity of radio fields generated in the region of the absorption chamber. The self-oscillating magnetometer can only operate provided that there is laser tuning to the long-wavelength component of the electric-dipole transition.

  13. All-optical low noise fiber Bragg grating microphone.

    PubMed

    Bandutunga, Chathura P; Fleddermann, Roland; Gray, Malcolm B; Close, John D; Chow, Jong H

    2016-07-20

    We present an all-fiber design for a microphone using a fiber Bragg grating Fabry-Perot resonator attached to a diaphragm transducer. We analytically model and verify the fiber-diaphragm mechanical interaction, using the Hänsch-Couillaud readout technique to provide necessary sensitivity. We achieved a noise-equivalent strain sensitivity of 7.1×10-12  ϵ/Hz, which corresponds to a sound pressure of 74  μPa/Hz at 1 kHz limited by laser frequency noise and yielding a signal-to-noise ratio of 47±2  dB with a 1 Pa drive at 1 kHz, in close agreement with modeled results.

  14. Polydimethylsiloxane thin film characterization using all-optical photoacoustic mechanism.

    PubMed

    Zou, Xiaotian; Wu, Nan; Tian, Ye; Zhang, Yang; Wang, Xingwei

    2013-09-01

    This paper presents a nondestructive ultrasound testing method for characterization of the resonant frequencies of polydimethylsiloxane (PDMS) thin film by using a miniature fiber optic photoacoustic (PA) probe. The PA probe was fabricated with an optical fiber and a synthesized gold nanocomposite. During the experiment, a cured PDMS thin film with a thickness of 220 μm was immersed into a water medium using a custom-designed holder to clamp the film. An acoustic pulse was generated by the PA probe and propagated through the water media to excite the fixed film. A fiber optic pressure sensor based on the Fabry-Perot principle was used to collect the excited acoustic signals on the other side of the film. The acquired response of the acoustic pulse was used to compute the resonant frequencies of the PDMS thin film based on a deconvolution method.

  15. New scheme of the microwave signal formation for quantum frequency standard on the atoms of caesium-133

    NASA Astrophysics Data System (ADS)

    Petrov, A. A.; Davydov, V. V.

    2016-11-01

    In present work several directions of quantum frequency standard modernization are considered. A new implementation of a frequency synthesizer and a magnetic field control unit are presented. Experimental study of a frequency synthesizer showed improvement parameters of a microwave-excitation signal, such as step frequency tuning, time frequency tuning, range of generating frequencies and spectral characteristics. Magnetic field control unit eliminates one of the most important perturbing factors affecting the long-term frequency stability. Daily frequency stability of quantum frequency standard improved on 15%.

  16. Ultrafast electrical spectrum analyzer based on all-optical Fourier transform and temporal magnification.

    PubMed

    Duan, Yuhua; Chen, Liao; Zhou, Haidong; Zhou, Xi; Zhang, Chi; Zhang, Xinliang

    2017-04-03

    Real-time electrical spectrum analysis is of great significance for applications involving radio astronomy and electronic warfare, e.g. the dynamic spectrum monitoring of outer space signal, and the instantaneous capture of frequency from other electronic systems. However, conventional electrical spectrum analyzer (ESA) has limited operation speed and observation bandwidth due to the electronic bottleneck. Therefore, a variety of photonics-assisted methods have been extensively explored due to the bandwidth advantage of the optical domain. Alternatively, we proposed and experimentally demonstrated an ultrafast ESA based on all-optical Fourier transform and temporal magnification in this paper. The radio-frequency (RF) signal under test is temporally multiplexed to the spectrum of an ultrashort pulse, thus the frequency information is converted to the time axis. Moreover, since the bandwidth of this ultrashort pulse is far beyond that of the state-of-the-art photo-detector, a temporal magnification system is applied to stretch the time axis, and capture the RF spectrum with 1-GHz resolution. The observation bandwidth of this ultrafast ESA is over 20 GHz, limited by that of the electro-optic modulator. Since all the signal processing is in the optical domain, the acquisition frame rate can be as high as 50 MHz. This ultrafast ESA scheme can be further improved with better dispersive engineering, and is promising for some ultrafast spectral information acquisition applications.

  17. Complete all-optical processing polarization-based binary logic gates and optical processors.

    PubMed

    Zaghloul, Y A; Zaghloul, A R M

    2006-10-16

    We present a complete all-optical-processing polarization-based binary-logic system, by which any logic gate or processor can be implemented. Following the new polarization-based logic presented in [Opt. Express 14, 7253 (2006)], we develop a new parallel processing technique that allows for the creation of all-optical-processing gates that produce a unique output either logic 1 or 0 only once in a truth table, and those that do not. This representation allows for the implementation of simple unforced OR, AND, XOR, XNOR, inverter, and more importantly NAND and NOR gates that can be used independently to represent any Boolean expression or function. In addition, the concept of a generalized gate is presented which opens the door for reconfigurable optical processors and programmable optical logic gates. Furthermore, the new design is completely compatible with the old one presented in [Opt. Express 14, 7253 (2006)], and with current semiconductor based devices. The gates can be cascaded, where the information is always on the laser beam. The polarization of the beam, and not its intensity, carries the information. The new methodology allows for the creation of multiple-input-multiple-output processors that implement, by itself, any Boolean function, such as specialized or non-specialized microprocessors. Three all-optical architectures are presented: orthoparallel optical logic architecture for all known and unknown binary gates, singlebranch architecture for only XOR and XNOR gates, and the railroad (RR) architecture for polarization optical processors (POP). All the control inputs are applied simultaneously leading to a single time lag which leads to a very-fast and glitch-immune POP. A simple and easy-to-follow step-by-step algorithm is provided for the POP, and design reduction methodologies are briefly discussed. The algorithm lends itself systematically to software programming and computer-assisted design. As examples, designs of all binary gates, multiple

  18. All-optical random number generation using highly nonlinear fibers by numerical simulation

    NASA Astrophysics Data System (ADS)

    Wang, Juanfen; Liang, Junqiang; Li, Pu; Yang, Lingzhen; Wang, Yuncai

    2014-06-01

    A new scheme of all-optical random number generation based on the nonlinear effects in highly nonlinear fibers (HNLF) is proposed. The scheme is comprised of ultra-wide band chaotic entropy source, all-optical sampler, all-optical comparator and all-optical exclusive-or (XOR), which are mainly realized by four-wave mixing (FWM) and cross-phase modulation (XPM) in highly nonlinear fibers. And we achieve 10 Gbit/s random numbers through numerically simulating all the processes. The entire operations are completed in the all-optical domain, which may overcome the bottleneck problem of electronic devices, and apply directly in high-speed all-optical communication network.

  19. Asynchronous, self-controlled, all-optical label and payload separator using nonlinear polarization rotation in a semiconductor optical amplifier.

    PubMed

    Vegas Olmos, J; Monroy, I; Liu, Y; Garcia Larrode, M; Turkiewicz, J; Dorren, H; Koonen, A

    2004-09-06

    We demonstrate an all-optical label and payload separator based on nonlinear polarization rotation in a semiconductor optical amplifier (SOA). The proposed scheme uses a packet format composed of a label and payload information signal combined with a control signal by using polarization division multiplexing. The control signal is employed to separate the label from the payload signal by exploiting nonlinear polarization rotation in a SOA. Experimental results show a label from payload suppression factor of 22 dB. This scheme operates asynchronously and does not need external control signal. Clean and wide open eye diagrams are obtained for both the payload and the label signal operating at bit-rates of 10 Gbit/s and 625 Mbit/s, respectively.

  20. All-optical packet routing scheme for optical label-swapping networks

    NASA Astrophysics Data System (ADS)

    Clavero, R.; Martínez, J. M.; Ramos, F.; Martí, J.

    2004-09-01

    A novel scheme for all-optical label reading and packet routing is proposed. The architecture is comprised of all-optical logic XOR gates and all-optical flip-flops based on single Mach-Zehnder interferometers incorporating semiconductor optical amplifiers (SOA-MZIs). The simulation results show that a very small penalty (less than 0.45 dB) for 10 Gbit/s packet processing can be achieved.

  1. All-optical optoacoustic microscopy system based on probe beam deflection technique

    NASA Astrophysics Data System (ADS)

    Maswadi, Saher M.; Tsyboulskic, Dmitri; Roth, Caleb C.; Glickman, Randolph D.; Beier, Hope T.; Oraevsky, Alexander A.; Ibey, Bennett L.

    2016-03-01

    It is difficult to achieve sub-micron resolution in backward mode OA microscopy using conventional piezoelectric detectors, because of wavefront distortions caused by components placed in the optical path, between the sample and the objective lens, that are required to separate the acoustic wave from the optical beam. As an alternate approach, an optoacoustic microscope (OAM) was constructed using the probe beam deflection technique (PBDT) to detect laserinduced acoustic signals. The all-optical OAM detects laser-generated pressure waves using a probe beam passing through a coupling medium, such as water, filling the space between the microscope objective lens and sample. The acoustic waves generated in the sample propagate through the coupling medium, causing transient changes in the refractive index that deflect the probe beam. These deflections are measured with a high-speed, balanced photodiode position detector. The deflection amplitude is directly proportional to the magnitude of the acoustic pressure wave, and provides the data required for image reconstruction. The sensitivity of the PBDT detector expressed as noise equivalent pressure was 12 Pa, comparable to that of existing high-performance ultrasound detectors. Because of the unimpeded working distance, a high numerical aperture objective lens, i.e. NA = 1, was employed in the OAM to achieve near diffraction-limited lateral resolution of 0.5 μm at 532nm. The all-optical OAM provides several benefits over current piezoelectric detector-based systems, such as increased lateral and axial resolution, higher sensitivity, robustness, and potentially more compatibility with multimodal instruments.

  2. All-optical switching of magnetoresistive devices using telecom-band femtosecond laser

    SciTech Connect

    He, Li; Chen, Jun-Yang; Wang, Jian-Ping E-mail: moli@umn.edu; Li, Mo E-mail: moli@umn.edu

    2015-09-07

    Ultrafast all-optical switching of the magnetization of various magnetic systems is an intriguing phenomenon that can have tremendous impact on information storage and processing. Here, we demonstrate all-optical switching of GdFeCo alloy films using a telecom-band femtosecond fiber laser. We further fabricate Hall cross devices and electrically readout all-optical switching by measuring anomalous Hall voltage changes. The use of a telecom laser and the demonstrated all-optical switching of magnetoresistive devices represent the first step toward integration of opto-magnetic devices with mainstream photonic devices to enable novel optical and spintronic functionalities.

  3. All-optical switching of magnetoresistive devices using telecom-band femtosecond laser

    NASA Astrophysics Data System (ADS)

    He, Li; Chen, Jun-Yang; Wang, Jian-Ping; Li, Mo

    2015-09-01

    Ultrafast all-optical switching of the magnetization of various magnetic systems is an intriguing phenomenon that can have tremendous impact on information storage and processing. Here, we demonstrate all-optical switching of GdFeCo alloy films using a telecom-band femtosecond fiber laser. We further fabricate Hall cross devices and electrically readout all-optical switching by measuring anomalous Hall voltage changes. The use of a telecom laser and the demonstrated all-optical switching of magnetoresistive devices represent the first step toward integration of opto-magnetic devices with mainstream photonic devices to enable novel optical and spintronic functionalities.

  4. Demonstration of all-optical phase noise suppression scheme using optical nonlinearity and conversion/dispersion delay.

    PubMed

    Chitgarha, Mohammad Reza; Khaleghi, Salman; Ziyadi, Morteza; Mohajerin-Ariaei, Amirhossein; Almaiman, Ahmed; Daab, Wajih; Rogawski, Devora; Tur, Moshe; Touch, Joseph D; Langrock, Carsten; Fejer, Martin M; Willner, Alan E

    2014-05-15

    We propose and demonstrate an all-optical phase noise reduction scheme that uses optical nonlinear mixing and tunable optical delays to suppress the low-speed phase noise induced by laser linewidth. By utilizing the phase conjugate copy of the original signal and two narrow-linewidth optical pumps, the phase noise induced by laser linewidth can be reduced by a factor of ∼5 for a laser with 500-MHz phase noise bandwidth. The error-vector-magnitude can be improved from ∼30% to ∼14% for the same laser linewidth for 40-Gbit/s quadrature phase shift keying signal.

  5. New microwave excitation signal generating circuit for quantum frequency standard on the atoms of caesium Cs133

    NASA Astrophysics Data System (ADS)

    Petrov, A. A.; Davydov, V. V.

    2016-03-01

    In this work the study, design, development and experimental results of a new microwave excitation signal generating circuit are presented. New design of this circuit is based on the method of direct digital synthesis. The results of theoretical calculations and experimental researches show that the new design not only has a high precision, but also has an improvement in the spectral characteristics of the output signal. Range of generated output frequencies is expanded, that leads to the possibility of detuning the frequency of the neighboring resonance of spectral line and adjust the C-field in quantum frequency standard. Experimental research of the metrological characteristics of the quantum frequency standard on the atoms of caesium with a new functional unit showed an improvement in the daily frequency stability.

  6. All-optical highly sensitive akinetic sensor for ultrasound detection and photoacoustic imaging

    PubMed Central

    Preisser, Stefan; Rohringer, Wolfgang; Liu, Mengyang; Kollmann, Christian; Zotter, Stefan; Fischer, Balthasar; Drexler, Wolfgang

    2016-01-01

    A novel all-optical akinetic ultrasound sensor, consisting of a rigid, fiber-coupled Fabry-Pérot etalon with a transparent central opening is presented. The sensing principle relies exclusively on the detection of pressure-induced changes of the refractive index in the fluid filling the Fabry-Pérot cavity. This enables resonance-free, inherently linear signal detection over a broad bandwidth. We demonstrate that the sensor achieves a exceptionally low peak noise equivalent pressure (NEP) values of 2 Pa over a 20 MHz measurement bandwidth (without signal averaging), while maintaining a flat frequency response, and a detection bandwidth up to 22.5 MHz (−6 dB). The measured large full field of view of the sensor is 2.7 mm × 1.3 mm and the dynamic range is 137 dB/Hz or 63 dB at 20 MHz bandwidth. For different required amplitude ranges the upper amplitude detection limit can be customized from at least 2 kPa to 2 MPa by using cavity mirrors with a lower optical reflectivity. Imaging tests on a resolution target and on biological tissue show the excellent suitability of the akinetic sensor for optical resolution photoacoustic microscopy (OR-PAM) applications. PMID:27867723

  7. Network connectivity enhancement by exploiting all optical multicast in semiconductor ring laser

    NASA Astrophysics Data System (ADS)

    Siraj, M.; Memon, M. I.; Shoaib, M.; Alshebeili, S.

    2015-03-01

    The use of smart phone and tablet applications will provide the troops for executing, controlling and analyzing sophisticated operations with the commanders providing crucial documents directly to troops wherever and whenever needed. Wireless mesh networks (WMNs) is a cutting edge networking technology which is capable of supporting Joint Tactical radio System (JTRS).WMNs are capable of providing the much needed bandwidth for applications like hand held radios and communication for airborne and ground vehicles. Routing management tasks can be efficiently handled through WMNs through a central command control center. As the spectrum space is congested, cognitive radios are a much welcome technology that will provide much needed bandwidth. They can self-configure themselves, can adapt themselves to the user requirement, provide dynamic spectrum access for minimizing interference and also deliver optimal power output. Sometimes in the indoor environment, there are poor signal issues and reduced coverage. In this paper, a solution utilizing (CR WMNs) over optical network is presented by creating nanocells (PCs) inside the indoor environment. The phenomenon of four-wave mixing (FWM) is exploited to generate all-optical multicast using semiconductor ring laser (SRL). As a result same signal is transmitted at different wavelengths. Every PC is assigned a unique wavelength. By using CR technology in conjunction with PC will not only solve network coverage issue but will provide a good bandwidth to the secondary users.

  8. All-Optical Cantilever-Enhanced Photoacoustic Spectroscopy in the Open Environment

    NASA Astrophysics Data System (ADS)

    Wei, Wei; Zhu, Yong; Lin, Cheng; Tian, Li; Xu, Zhuwen; Nong, Jinpeng

    2015-06-01

    A novel all-optical cantilever-enhanced photoacoustic spectroscopy technique for trace gas detection in the open environment is proposed. A cantilever is set off-beam to "listen to" the photoacoustic signal, and an improved quadrature-point stabilization Fabry-Perot demodulation unit is used to pick up the vibration signal of the acoustic transducer instead of a complicated Michelson interferometer. The structure parameters of the cantilever are optimized to make the sensing system work more stably and reliably using a finite element method, which is then fabricated by surface micro-machining technology. Finally, related experiments are carried out to detect the absorption of water vapor at one atmosphere in the open environment. It was found that the normalized noise-equivalent absorption coefficient obtained by a traditional Fabry-Perot demodulation unit is , while that by a quadrature- point stabilization Fabry-Perot demodulation unit is , which indicates that the sensitivity is increased by a factor of 3.1 using improved cantilever-enhanced photoacoustic spectroscopy.

  9. Current Developments on Optical Feedback Interferometry as an All-Optical Sensor for Biomedical Applications

    PubMed Central

    Perchoux, Julien; Quotb, Adam; Atashkhooei, Reza; Azcona, Francisco J.; Ramírez-Miquet, Evelio E.; Bernal, Olivier; Jha, Ajit; Luna-Arriaga, Antonio; Yanez, Carlos; Caum, Jesus; Bosch, Thierry; Royo, Santiago

    2016-01-01

    Optical feedback interferometry (OFI) sensors are experiencing a consistent increase in their applications to biosensing due to their contactless nature, low cost and compactness, features that fit very well with current biophotonics research and market trends. The present paper is a review of the work in progress at UPC-CD6 and LAAS-CNRS related to the application of OFI to different aspects of biosensing, both in vivo and ex vivo. This work is intended to present the variety of opportunities and potential applications related to OFI that are available in the field. The activities presented are divided into two main sensing strategies: The measurement of optical path changes and the monitoring of flows, which correspond to sensing strategies linked to the reconstruction of changes of amplitude from the interferometric signal, and to classical Doppler frequency measurements, respectively. For optical path change measurements, measurements of transient pulses, usual in biosensing, together with the measurement of large displacements applied to designing palliative care instrumentation for Parkinson disease are discussed. Regarding the Doppler-based approach, progress in flow-related signal processing and applications in real-time monitoring of non-steady flows, human blood flow monitoring and OFI pressure myograph sensing will be presented. In all cases, experimental setups are discussed and results presented, showing the versatility of the technique. The described applications show the wide capabilities in biosensing of the OFI sensor, showing it as an enabler of low-cost, all-optical, high accuracy biomedical applications. PMID:27187406

  10. Demonstration and performance investigation of all-optical OFDM systems based on arrayed waveguide gratings.

    PubMed

    Shimizu, Satoshi; Cincotti, Gabriella; Wada, Naoya

    2012-12-10

    We experimentally demonstrate an 8 x 12.5 Gbit/s all-optical orthogonal frequency-division multiplexing (AO-OFDM) system using arrayed waveguide gratings (AWGs), which perform discrete Fourier transform (DFT) and inverse DFT (IDFT) of a signal directly in the optical domain. The experimental results show that frequency orthogonality of OFDM sub-channels is degraded in the AWG due to the slab-diffraction effect. To restore the frequency orthogonality and improve the system performance, we propose and demonstrate a waveform reshaping scheme, that improve the bit-error-rate (BER) from 10(-4) to 10(-6). We also experimentally investigate the influence of frequency mismatch between the OFDM signal and AWG at the receiver. The measured BER shows a serious degradation from 10(-6) to 10(-4) in case of ± 1.88 GHz frequency mismatch. To keep the BER under 10(-5), the frequency mismatch should be smaller than ± 0.5 GHz ( ± 4% of the channel spacing).

  11. All optical fiber combined-imaging system of photoacoustic and optical coherence tomography

    NASA Astrophysics Data System (ADS)

    Eom, Jonghyun; Shin, Jun Geun; Park, Soongho; Lee, Byeong Ha

    2016-03-01

    We present an all optical fiber combined-imaging system that integrates non-contact photoacoustic tomography (NPAT) and optical coherence tomography (OCT) to simultaneously provide PA and OCT images. The fiber-based PAT system utilizing a Mach-Zehnder interferometer with a fiber laser of 1550 nm measures the photoacoustic signal at the sample surface. For the generation of a PA signal, a pulse train from a bulk type Nd:YAG laser illuminates the sample via a large core multimode optical fiber. The fiber-based OCT operating at a center wavelength of 1310 nm allowed is combined with the fiber-based PAT system by sharing the same optical fiber probe. The two lights from the fiber laser and the OCT source are guided into the probe through each port of a 2 by 2 optical fiber coupler. The back-reflected lights from the sample are guided to respective imaging systems by the same coupler. With these both NPAT and OCT images could be co-registered without physical contact with the sample. To demonstrate the feasibility of the proposed system, a phantom experiment has been carried out with a phantom composed of a black PET fiber and a fishing wire. The proposed all fiber-optic combined-imaging system has the potential for minimally invasive and improved diagnosis.

  12. Phase-coded microwave signal generation based on a single electro-optical modulator and its application in accurate distance measurement.

    PubMed

    Zhang, Fangzheng; Ge, Xiaozhong; Gao, Bindong; Pan, Shilong

    2015-08-24

    A novel scheme for photonic generation of a phase-coded microwave signal is proposed and its application in one-dimension distance measurement is demonstrated. The proposed signal generator has a simple and compact structure based on a single dual-polarization modulator. Besides, the generated phase-coded signal is stable and free from the DC and low-frequency backgrounds. An experiment is carried out. A 2 Gb/s phase-coded signal at 20 GHz is successfully generated, and the recovered phase information agrees well with the input 13-bit Barker code. To further investigate the performance of the proposed signal generator, its application in one-dimension distance measurement is demonstrated. The measurement accuracy is less than 1.7 centimeters within a measurement range of ~2 meters. The experimental results can verify the feasibility of the proposed phase-coded microwave signal generator and also provide strong evidence to support its practical applications.

  13. Photonic generation of stable microwave signals from a dual-wavelength Al2O3:Yb3+ distributed-feedback waveguide laser.

    PubMed

    Bernhardi, E H; Khan, M R H; Roeloffzen, C G H; van Wolferen, H A G M; Wörhoff, K; de Ridder, R M; Pollnau, M

    2012-01-15

    We report the fabrication and characterization of a dual-wavelength distributed-feedback channel waveguide laser in ytterbium-doped aluminum oxide. Operation of the device is based on the optical resonances that are induced by two local phase shifts in the distributed-feedback structure. A stable microwave signal at ~15 GHz with a -3 dB width of 9 kHz was subsequently created via the heterodyne photodetection of the two laser wavelengths. The long-term frequency stability of the microwave signal produced by the free-running laser is better than ±2.5 MHz, while the power of the microwave signal is stable within ±0.35 dB.

  14. Derivation of a global soil moisture and vegetation database from passive microwave signals

    NASA Astrophysics Data System (ADS)

    De Jeu, Richard A. M.; Owe, Manfred

    2003-03-01

    A series of validation studies for a recently developed soil moisture retrieval algorithm is presented. The approach is largely theoretical, and uses a non-linear iterative optimisation procedure to solve for soil moisture and vegetation optical depth with a radiative transfer model from satellite microwave observations. The new theoretical approach is not dependent on field observations of soil moisture or canopy biophysical measurements and can be used at any wavelength in the microwave region. Details of the model and its development are discussed. Satellite retrievals were derived from 6.6 GHz Nimbus/SMMR brightness temperatures, and were validated with soil moisture data sets from the U.S., Mongolia, and Turkmenistan. Time series of the satellite-derived surface moisture compared well with the available ground observations and precipitation data. The vegetation optical depth showed similar seasonal patterns as the NDVI.

  15. All-optical photoacoustic imaging and detection of early-stage dental caries

    NASA Astrophysics Data System (ADS)

    Sampathkumar, Ashwin; Hughes, David A.; Longbottom, Chris; Kirk, Katherine J.

    2015-02-01

    Dental caries remain one of the most common oral diseases in the world. Current detection methods, such as dental explorer and X-ray radiography, suffer from poor sensitivity and specificity at the earliest (and reversible) stages of the disease because of the small size (< 100 microns) of early-stage lesions. We have developed a fine-resolution (480 nm), ultra-broadband (1 GHz), all-optical photoacoustic imaging (AOPAI) system to image and detect early stages of tooth decay. This AOPAI system provides a non-contact, non-invasive and non-ionizing means of detecting early-stage dental caries. Ex-vivo teeth exhibiting early-stage, white-spot lesions were imaged using AOPAI. Experimental scans targeted each early-stage lesion and a reference healthy enamel region. Photoacoustic (PA) signals were generated in the tooth using a 532-nm pulsed laser and the light-induced broadband ultrasound signal was detected at the surface of the tooth with an optical path-stabilized Michelson interferometer operating at 532 nm. The measured time-domain signal was spatially resolved and back-projected to form 2D and 3D maps of the lesion using k-wave reconstruction methods. Experimental data collected from areas of healthy and diseased enamel indicate that the lesion generated a larger PA response compared to healthy enamel. The PA-signal amplitude alone was able to detect a lesion on the surface of the tooth. However, time- reversal reconstructions of the PA scans also quantitatively depicted the depth of the lesion. 3D PA reconstruction of the diseased tooth indicated a sub-surface lesion at a depth of 0.6 mm, in addition to the surface lesion. These results suggest that our AOPAI system is well suited for rapid clinical assessment of early-stage dental caries. An overview of the AOPAI system, fine-resolution PA and histology results of diseased and healthy teeth will be presented.

  16. A MARKOV CHAIN MONTE CARLO ALGORITHM FOR ANALYSIS OF LOW SIGNAL-TO-NOISE COSMIC MICROWAVE BACKGROUND DATA

    SciTech Connect

    Jewell, J. B.; O'Dwyer, I. J.; Huey, Greg; Gorski, K. M.; Eriksen, H. K.; Wandelt, B. D. E-mail: h.k.k.eriksen@astro.uio.no

    2009-05-20

    We present a new Markov Chain Monte Carlo (MCMC) algorithm for cosmic microwave background (CMB) analysis in the low signal-to-noise regime. This method builds on and complements the previously described CMB Gibbs sampler, and effectively solves the low signal-to-noise inefficiency problem of the direct Gibbs sampler. The new algorithm is a simple Metropolis-Hastings sampler with a general proposal rule for the power spectrum, C {sub l}, followed by a particular deterministic rescaling operation of the sky signal, s. The acceptance probability for this joint move depends on the sky map only through the difference of {chi}{sup 2} between the original and proposed sky sample, which is close to unity in the low signal-to-noise regime. The algorithm is completed by alternating this move with a standard Gibbs move. Together, these two proposals constitute a computationally efficient algorithm for mapping out the full joint CMB posterior, both in the high and low signal-to-noise regimes.

  17. Demonstration and characterisation of a non-inverting all-optical read/write regenerative memory

    NASA Astrophysics Data System (ADS)

    Johnson, N. C.; Harrison, J. A.; Blow, K. J.

    2008-09-01

    An all-optical regenerative memory device using a single loop mirror and a semiconductor optical amplifier is experimentally demonstrated. This configuration has potential for a low power all-optical stable memory device with non-inverting characteristics where packets are stored by continuously injecting the regenerated data back into the loop.

  18. System tolerance of all-optical sampling OFDM using AWG discrete Fourier transform.

    PubMed

    Lim, Seong-Jin; Rhee, June-Koo Kevin

    2011-07-04

    The fundamental-mode arrayed waveguide grating (AWG) for all-optical discrete Fourier transformer (DFT) shows significant feasibility in the system tolerance of all-optical sampling orthogonal frequency division multiplexing (AOS-OFDM) systems. We discuss the system tolerance of AWG-based DFT designs for 100/160Gbps OFDM transmission system in comparison with coupler-based DFT designs.

  19. Ultrafast all-optical switching with photonic nanojets and semiconductor nanoparticles

    NASA Astrophysics Data System (ADS)

    Born, Brandon; Krupa, Jeffrey D. A.; Geoffroy-Gagnon, Simon; Holzman, Jonathan F.

    2016-03-01

    The potential of terabit-per-second fibre optics can be unlocked with emerging all-optical networks and processors employing all-optical switching. To be effective, all-optical switching must support operations with femtojoule switching energies and femtosecond switching times. With this in mind, this work studies geometrical and material characteristics for all-optical switching and develops a new all-optical switching architecture. A nanojet focal geometry is applied, in the form of dielectric spheres, to direct high-intensity photonic nanojets into peripheral semiconductors. Theoretical and experimental analyses demonstrate photonic nanojets, enabling femtojoule switching energies through localized photoinjection, and semiconductor nanoparticles, enabling femtosecond switching times through localized recombination.

  20. A low cost technique for synthesis of gold nanoparticles using microwave heating and its application in signal amplification for detecting Escherichia Coli O157:H7 bacteria

    NASA Astrophysics Data System (ADS)

    Thanh Ngo, Vo Ke; Giang Nguyen, Dang; Phat Huynh, Trong; Lam, Quang Vinh

    2016-09-01

    In the present work a low cost technique for preparation of gold nanoparticles (AuNPs) using microwave heating was developed. The effect of different elements (precursor reagents, irradiation time, and microwave radiation power) on the final morphology of AuNPs obtained through the microwave assisted technique has been investigated. The characterization of the samples has been carried out by transmission electron microscopy, UV-vis absorption spectroscopy, Fourier transform infrared spectroscopy, and powder x-ray diffraction. The results showed that to some extent the above-mentioned characterizations influenced the size of synthetized nanoparticles and application of microwave heating has many advantages such as low cost, rapid preparation and highly uniform particles. As an application in quartz crystal microbalance (QCM) immunosensor, AuNPs are conjugated with the Escherichia coli (E.coli) O157:H7 antibodies for signal amplification to detect E.coli O157:H7 bacteria residual in QCM system.

  1. A metro-access integrated network with all-optical virtual private network function using DPSK/ASK modulation format

    NASA Astrophysics Data System (ADS)

    Tian, Yue; Leng, Lufeng; Su, Yikai

    2008-11-01

    All-optical virtual private network (VPN), which offers dedicated optical channels to connect users within a VPN group, is considered a promising approach to efficient internetworking with low latency and enhanced security implemented in the physical layer. On the other hand, time-division multiplexed (TDM) / wavelength-division multiplexed (WDM) network architecture based on a feeder-ring with access-tree topology, is considered a pragmatic migration scenario from current TDM-PONs to future WDM-PONs and a potential convergence scheme for access and metropolitan networks, due to its efficiently shared hardware and bandwidth resources. All-optical VPN internetworking in such a metro-access integrated structure is expected to cover a wider service area and therefore is highly desirable. In this paper, we present a TDM/WDM metro-access integrated network supporting all-optical VPN internetworking among ONUs in different sub- PONs based on orthogonal differential-phase-shift keying (DPSK) / amplitude-shift keying (ASK) modulation format. In each ONU, no laser but a single Mach-Zehnder modulator (MZM) is needed for the upstream and VPN signal generation, which is cost-effective. Experiments and simulations are performed to verify its feasibility as a potential solution to the future access service.

  2. All-optical switching with bacteriorhodopsin protein coated microcavities and its application to low power computing circuits

    NASA Astrophysics Data System (ADS)

    Roy, Sukhdev; Prasad, Mohit; Topolancik, Juraj; Vollmer, Frank

    2010-03-01

    We show all-optical switching of an input infrared laser beam at 1310 nm by controlling the photoinduced retinal isomerization to tune the resonances in a silica microsphere coated with three bacteriorhodopsin (BR) protein monolayers. The all-optical tunable resonant coupler re-routes the infrared beam between two tapered fibers in 50 μs using a low power (<200 μW) green (532 nm) and blue (405 nm) pump beams. The basic switching configuration has been used to design all-optical computing circuits, namely, half and full adder/subtractor, de-multiplexer, multiplexer, and an arithmetic unit. The design requires 2n-1 switches to realize n bit computation. The designs combine the exceptional sensitivities of BR and high-Q microcavities and the versatile tree architecture for realizing low power circuits and networks (approximately mW power budget). The combined advantages of high Q-factor, tunability, compactness, and low power control signals, with the flexibility of cascading switches to form circuits, and reversibility and reconfigurability to realize arithmetic and logic functions, makes the designs promising for practical applications. The designs are general and can be implemented (i) in both fiber-optic and integrated optic formats, (ii) with any other coated photosensitive material, or (iii) any externally controlled microresonator switch.

  3. Microwave Oscillators Based on Nonlinear WGM Resonators

    NASA Technical Reports Server (NTRS)

    Maleki, Lute; Matsko, Andrey; Savchenkov, Anatoliy; Strekalov, Dmitry

    2006-01-01

    Optical oscillators that exploit resonantly enhanced four-wave mixing in nonlinear whispering-gallery-mode (WGM) resonators are under investigation for potential utility as low-power, ultra-miniature sources of stable, spectrally pure microwave signals. There are numerous potential uses for such oscillators in radar systems, communication systems, and scientific instrumentation. The resonator in an oscillator of this type is made of a crystalline material that exhibits cubic Kerr nonlinearity, which supports the four-photon parametric process also known as four-wave mixing. The oscillator can be characterized as all-optical in the sense that the entire process of generation of the microwave signal takes place within the WGM resonator. The resonantly enhanced four-wave mixing yields coherent, phase-modulated optical signals at frequencies governed by the resonator structure. The frequency of the phase-modulation signal, which is in the microwave range, equals the difference between the frequencies of the optical signals; hence, this frequency is also governed by the resonator structure. Hence, further, the microwave signal is stable and can be used as a reference signal. The figure schematically depicts the apparatus used in a proof-of-principle experiment. Linearly polarized pump light was generated by an yttrium aluminum garnet laser at a wavelength of 1.32 microns. By use of a 90:10 fiber-optic splitter and optical fibers, some of the laser light was sent into a delay line and some was transmitted to one face of glass coupling prism, that, in turn, coupled the laser light into a crystalline CaF2 WGM disk resonator that had a resonance quality factor (Q) of 6x10(exp 9). The output light of the resonator was collected via another face of the coupling prism and a single-mode optical fiber, which transmitted the light to a 50:50 fiber-optic splitter. One output of this splitter was sent to a slow photodiode to obtain a DC signal for locking the laser to a particular

  4. Distributed All-Optical Sensor to Detect dCO2 in Aqueous Environments

    NASA Astrophysics Data System (ADS)

    Bhatia, S.; Coelho, J.; Melo, L.; Davies, B.; Ahmed, F.; Bao, B.; Wild, P.; Risk, D. A.; Sinton, D.; Jun, M.

    2012-12-01

    Already a proven technology for temperature and stress measurements, an all-optical sensor to detect dCO2 is being developed for deployment in challenging environments. Optical sensors function under high pressure, do not require electronics and therefore experience no magnetic interference. They are also able to transmit signals over long distances with minimal losses. The dCO2 sensor's principal application is in measurement monitoring and verification of carbon capture and storage sites; however, it could also be useful in ocean, fresh water, and transition environments. The objective for the first phase of development was to detect a CO2 signal in laboratory tests. The developmental program incorporated experiments to detect CO2 under high pressure (1400 psi) in aqueous environments. Laboratory testing involved a custom pressure cell, off-the-shelf and custom long period gratings written in SMF125 fiber. Femptosecond laser micromachining was used to test alternative long period grating (LPG) and cutout shapes to maximize evanescent field interaction with the environment. A comprehensive program of geochemical modeling using PHREEQC 2 was used to identify the diversity of species in environments of interest that could exert confounding influence. Purchased UV-LPG responded to changes in concentration of scCO2 in brine at high pressure. Signal differences between CO2-saturated brine and pure brine were also noted under the same, high pressure conditions. Geochemical modeling software, PHREEQC 2, revealed a diversity of species in environments of interest whose concentrations varied strongly with temperature and pH. The modeling program's detailed characterization of environments informed work currently being undertaken as part of Phase 2, to develop a CO2-selective membrane to filter out measurement artifact.

  5. All-optical modulation in Mid-Wavelength Infrared using porous Si membranes

    PubMed Central

    Park, Sung Jin; Zakar, Ammar; Zerova, Vera L.; Chekulaev, Dimitri; Canham, Leigh T.; Kaplan, Andre

    2016-01-01

    We demonstrate for the first time the possibility of all-optical modulation of self-standing porous Silicon (pSi) membrane in the Mid-Wavelength Infrared (MWIR) range using femtosecond pump-probe techniques. To study optical modulation, we used pulses of an 800 nm, 60 femtosecond for pump and a MWIR tunable probe in the spectral range between 3.5 and 4.4 μm. We show that pSi possesses a natural transparency window centred around 4 μm. Yet, about 55% of modulation contrast can be achieved by means of optical excitation at the pump power of 60 mW (4.8 mJ/cm2). Our analysis shows that the main mechanism of the modulation is interaction of the MWIR signal with the free charge carrier excited by the pump. The time-resolved measurements showed a sub-picosecond rise time and a recovery time of about 66 ps, which suggests a modulation speed performance of ~15 GHz. This optical modulation of pSi membrane in MWIR can be applied to a variety of applications such as thermal imaging and free space communications. PMID:27440224

  6. All-optical modulation in Mid-Wavelength Infrared using porous Si membranes.

    PubMed

    Park, Sung Jin; Zakar, Ammar; Zerova, Vera L; Chekulaev, Dimitri; Canham, Leigh T; Kaplan, Andre

    2016-07-21

    We demonstrate for the first time the possibility of all-optical modulation of self-standing porous Silicon (pSi) membrane in the Mid-Wavelength Infrared (MWIR) range using femtosecond pump-probe techniques. To study optical modulation, we used pulses of an 800 nm, 60 femtosecond for pump and a MWIR tunable probe in the spectral range between 3.5 and 4.4 μm. We show that pSi possesses a natural transparency window centred around 4 μm. Yet, about 55% of modulation contrast can be achieved by means of optical excitation at the pump power of 60 mW (4.8 mJ/cm(2)). Our analysis shows that the main mechanism of the modulation is interaction of the MWIR signal with the free charge carrier excited by the pump. The time-resolved measurements showed a sub-picosecond rise time and a recovery time of about 66 ps, which suggests a modulation speed performance of ~15 GHz. This optical modulation of pSi membrane in MWIR can be applied to a variety of applications such as thermal imaging and free space communications.

  7. All-optical modulation in Mid-Wavelength Infrared using porous Si membranes

    NASA Astrophysics Data System (ADS)

    Park, Sung Jin; Zakar, Ammar; Zerova, Vera L.; Chekulaev, Dimitri; Canham, Leigh T.; Kaplan, Andre

    2016-07-01

    We demonstrate for the first time the possibility of all-optical modulation of self-standing porous Silicon (pSi) membrane in the Mid-Wavelength Infrared (MWIR) range using femtosecond pump-probe techniques. To study optical modulation, we used pulses of an 800 nm, 60 femtosecond for pump and a MWIR tunable probe in the spectral range between 3.5 and 4.4 μm. We show that pSi possesses a natural transparency window centred around 4 μm. Yet, about 55% of modulation contrast can be achieved by means of optical excitation at the pump power of 60 mW (4.8 mJ/cm2). Our analysis shows that the main mechanism of the modulation is interaction of the MWIR signal with the free charge carrier excited by the pump. The time-resolved measurements showed a sub-picosecond rise time and a recovery time of about 66 ps, which suggests a modulation speed performance of ~15 GHz. This optical modulation of pSi membrane in MWIR can be applied to a variety of applications such as thermal imaging and free space communications.

  8. All optical FMR of ferromagnetic (Ga,Mn)As with various Mn contents

    NASA Astrophysics Data System (ADS)

    Kobayashi, Satoi; Hashimoto, Yusuke; Munekata, Hiro

    2008-03-01

    We have investigated all-optical FMR of non-thermal origin [1] on (Ga,Mn)As with various Mn contents x with time-resolve MO signals obtained by a single-wavelength pump and probe (P&P) technique, and found clear dependence of x on the effective magnetic field on ferromagnetically coupled Mn spins. (Ga,Mn)As samples x = 0.02-0.11 were grown by molecular beam epitaxy. Measurements were performed for both as-grown and annealed samples. In-plane magnetization easy axis was [1-10] for the x = 0.11 sample, whereas it was <100> for the rest. Samples were magnetized prior to P&P measurements. Polarization of probe pulses was carefully controlled with respect to the direction of M. Pump power was varied between 3.4 - 34 μJ/cm^2. Precession of magnetization was clearly observed at 10-40 K in most of samples. The period of the oscillation becomes longer with increasing x value, indicating a decrease in an effective magnetic field Heff = φ / gμB on Mn spins from 0.2 to 0.1 Tesla with increasing x. Assuming Heff=Jpd with constant Jpd, the observed trend suggests the reduction in the mean spin density of holes with increasing x. [1] Y. Hashimoto and H. Munekata, arXiv: 0707.4055v2; H. Takechi et al., phys. stat. sol. (c) 3, 4267 (2006).

  9. N-bits all-optical circular shift register based on semiconductor optical amplifier buffer

    NASA Astrophysics Data System (ADS)

    Lazzeri, Emma; Berrettini, Gianluca; Meloni, Gianluca; Bogoni, Antonella; Potì, Luca

    2011-03-01

    In the perspective of a future all-optical communication network optical shift register will play an important role especially for what concerns several binary functions, such as serial to parallel conversion and cyclic operations, that are involved in techniques allowing error detection and correction as parity check, or cyclic redundancy check. During the last decades, several attempts of realizing circulating memories or shift register in the optical domain were made, with some limits in terms of functionality, number of bit to be stored (under three), scalability or photonic integrability. In this paper, we present a new approach to realize a circulating optical shift register consisting on an SOA-based optical buffer (OB) and a bit selecting circuit (BSC). The OB is potentially integrable and is able to store a finite number of bit at high bit rate. The BSC returns consecutive bits at a lower clock rate, achieving proper shift register function. The bit selection is realized by means of four wave mixing (FWM) in a Kerr medium, and the sequence cancellation is allowed to enable new sequence storing. Experimental validation of the scheme for fB=59MHz and fB=236MHz shows optical signal to noise ratio per bit penalty of 5.6dB at BER=10-9.

  10. Imaging and detection of early stage dental caries with an all-optical photoacoustic microscope

    NASA Astrophysics Data System (ADS)

    Hughes, D. A.; Sampathkumar, A.; Longbottom, C.; Kirk, K. J.

    2015-01-01

    Tooth decay, at its earliest stages, manifests itself as small, white, subsurface lesions in the enamel. Current methods for detection in the dental clinic are visual and tactile investigations, and bite-wing X-ray radiographs. These techniques suffer from poor sensitivity and specificity at the earliest (and reversible) stages of the disease due to the small size (<100μm) of the lesion. A fine-resolution (600 nm) ultra-broadband (200 MHz) all-optical photoacoustic microscopy system was is used to image the early signs of tooth decay. Ex-vivo tooth samples exhibiting white spot lesions were scanned and were found to generate a larger (one order of magnitude) photoacoustic (PA) signal in the lesion regions compared to healthy enamel. The high contrast in the PA images potentially allows lesions to be imaged and measured at a much earlier stage than current clinical techniques allow. PA images were cross referenced with histology photographs to validate our experimental results. Our PA system provides a noncontact method for early detection of white-spot lesions with a high detection bandwidth that offers advantages over previously demonstrated ultrasound methods. The technique provides the sensing depth of an ultrasound system, but with the spatial resolution of an optical system.

  11. Ultracompact all-optical XOR logic gate in a slow-light silicon photonic crystal waveguide.

    PubMed

    Husko, C; Vo, T D; Corcoran, B; Li, J; Krauss, T F; Eggleton, B J

    2011-10-10

    We demonstrate an ultracompact, chip-based, all-optical exclusive-OR (XOR) logic gate via slow-light enhanced four-wave mixing (FWM) in a silicon photonic crystal waveguide (PhCWG). We achieve error-free operation (<10⁻⁹) for 40 Gbit/s differential phase-shift keying (DPSK) signals with a 2.8 dB power penalty. Slowing the light to vg = c/32 enables a FWM conversion efficiency, η, of -30 dB for a 396 μm device. The nonlinear FWM process is enhanced by 20 dB compared to a relatively fast mode of vg = c/5. The XOR operation requires ≈ 41 mW, corresponding to a switching energy of 1 pJ/bit. We compare the slow-light PhCWG device performance with experimentally demonstrated XOR DPSK logic gates in other platforms and discuss scaling the device operation to higher bit-rates. The ultracompact structure suggests the potential for device integration.

  12. All-optical logic gates and wavelength conversion via the injection locking of a Fabry-Perot semiconductor laser

    NASA Astrophysics Data System (ADS)

    Harvey, E.; Pochet, M.; Schmidt, J.; Locke, T.; Naderi, N.; Usechak, N. G.

    2013-03-01

    This work investigates the implementation of all-optical logic gates based on optical injection locking (OIL). All-optical inverting, NOR, and NAND gates are experimentally demonstrated using two distributed feedback (DFB) lasers, a multi-mode Fabry-Perot laser diode, and an optical band-pass filter. The DFB lasers are externally modulated to represent logic inputs into the cavity of the multi-mode Fabry-Perot slave laser. The input DFB (master) lasers' wavelengths are aligned with the longitudinal modes of the Fabry-Perot slave laser and their optical power is used to modulate the injection conditions in the Fabry-Perot slave laser. The optical band-pass filter is used to select a Fabry- Perot mode that is either suppressed or transmitted given the logic state of the injecting master laser signals. When the input signal(s) is (are) in the on state, injection locking, and thus the suppression of the non-injected Fabry-Perot modes, is induced, yielding a dynamic system that can be used to implement photonic logic functions. Additionally, all-optical photonic processing is achieved using the cavity-mode shift produced in the injected slave laser under external optical injection. The inverting logic case can also be used as a wavelength converter — a key component in advanced wavelength-division multiplexing networks. As a result of this experimental investigation, a more comprehensive understanding of the locking parameters involved in injecting multiple lasers into a multi-mode cavity and the logic transition time is achieved. The performance of optical logic computations and wavelength conversion has the potential for ultrafast operation, limited primarily by the photon decay rate in the slave laser.

  13. Nonreciprocal Microwave Signal Processing with a Field-Programmable Josephson Amplifier

    NASA Astrophysics Data System (ADS)

    Lecocq, F.; Ranzani, L.; Peterson, G. A.; Cicak, K.; Simmonds, R. W.; Teufel, J. D.; Aumentado, J.

    2017-02-01

    We report on the design and implementation of a field-programmable Josephson amplifier (FPJA)—a compact and lossless superconducting circuit that can be programmed in situ by a set of microwave drives to perform reciprocal and nonreciprocal frequency conversion and amplification. In this work, we demonstrate four modes of operation: frequency conversion (transmission of -0.5 dB, reflection of -30 dB), circulation (transmission of -0.5 dB, reflection of -30 dB, isolation of 30 dB), phase-preserving amplification (gain >20 dB , one photon of added noise) and directional phase-preserving amplification (reflection of -10 dB, forward gain of 18 dB, reverse isolation of 8 dB, one photon of added noise). The system exhibits quantitative agreement with the theoretical prediction. Based on a gradiometric superconducting quantum-interference device with Nb /Al -Al Ox/Nb Josephson junctions, the FPJA is first-order insensitive to flux noise and can be operated without magnetic shielding at low temperature. Owing to its flexible design and compatibility with existing superconducting fabrication techniques, the FPJA offers a straightforward route toward on-chip integration with superconducting quantum circuits such as qubits and microwave optomechanical systems.

  14. A novel 40-Gb/s all-optical inverted wavelength converter based on a modified terahertz optical asymmetric demultiplexer

    NASA Astrophysics Data System (ADS)

    Huang, Xuetian; Ye, Peida; Zhang, Min; Wang, Ling

    2004-12-01

    A novel scheme for all-optical inverted wavelength conversion with 40-Gb/s pseudorandom bit sequences (PRBSs) based on a modified terahertz optical asymmetric demultiplexer (TOAD) is proposed. The performance of the proposed wavelength converter is analyzed in term of extinction ratio (ER) through numerical simulations. For a typical ER of 10 dB, some key characteristic parameters of the semiconductor optical amplifier (SOA) are designed. With the properly designed parameters, a high quality eye diagram is achievable, indicating that the amplitude fluctuation of the output signal is effectively reduced.

  15. Line space theory of Resonant Four-Wave Mixing: New prospects for all-optical studies of photofragment states

    NASA Astrophysics Data System (ADS)

    Kouzov, A. P.; Radi, P. P.

    2017-04-01

    Based on the line-space quantum formalism, the potential of Resonant Four-Wave Mixing spectroscopy as a new tool to study rotational and translational anisotropy of photofragments produced by absorption of plane-polarized photons is theoretically addressed. Synergy of the flexible polarization setup, fine quantum state resolution and of the possibility to study translational recoil distributions, makes the tool unsurpassed among the all-optical means to interrogate the photofragment states. It allows to directly separate signals induced by the rotational anisotropy which remain silent in the most of laser-induced fluorescence responses and thus opens new ways to study rotational helicity, a crucial signature of the photolysis pathway.

  16. On-chip integratable all-optical quantizer using strong cross-phase modulation in a silicon-organic hybrid slot waveguide

    PubMed Central

    Kang, Zhe; Yuan, Jinhui; Zhang, Xianting; Sang, Xinzhu; Wang, Kuiru; Wu, Qiang; Yan, Binbin; Li, Feng; Zhou, Xian; Zhong, Kangping; Zhou, Guiyao; Yu, Chongxiu; Farrell, Gerald; Lu, Chao; Yaw Tam, Hwa; Wai, P. K. A.

    2016-01-01

    High performance all-optical quantizer based on silicon waveguide is believed to have significant applications in photonic integratable optical communication links, optical interconnection networks, and real-time signal processing systems. In this paper, we propose an integratable all-optical quantizer for on-chip and low power consumption all-optical analog-to-digital converters. The quantization is realized by the strong cross-phase modulation and interference in a silicon-organic hybrid (SOH) slot waveguide based Mach-Zehnder interferometer. By carefully designing the dimension of the SOH waveguide, large nonlinear coefficients up to 16,000 and 18,069 W−1/m for the pump and probe signals can be obtained respectively, along with a low pulse walk-off parameter of 66.7 fs/mm, and all-normal dispersion in the wavelength regime considered. Simulation results show that the phase shift of the probe signal can reach 8π at a low pump pulse peak power of 206 mW and propagation length of 5 mm such that a 4-bit all-optical quantizer can be realized. The corresponding signal-to-noise ratio is 23.42 dB and effective number of bit is 3.89-bit. PMID:26777054

  17. Photonic generation of widely tunable phase-coded microwave signals based on a dual-parallel polarization modulator.

    PubMed

    Liu, Shifeng; Zhu, Dan; Wei, Zhengwu; Pan, Shilong

    2014-07-01

    A photonic approach for the generation of a widely tunable arbitrarily phase-coded microwave signal based on a dual-parallel polarization modulator (DP-PolM) is proposed and demonstrated without using any optical or electrical filter. Two orthogonally polarized ± first-order optical sidebands with suppressed carrier are generated based on the DP-PolM, and their polarization directions are aligned with the two principal axes of the following PolM. Phase coding is implemented at a following PolM driven by an electrical coding signal. The inherent frequency-doubling operation can make the system work at a frequency beyond the operation bandwidth of the DP-PolM and the 90° hybrid. Because no optical or electrical filter is applied, good frequency tunability is realized. An experiment is performed. The generation of phase-coded signals tuning from 10 to 40 GHz with up to 10  Gbit/s coding rates is verified.

  18. High bandwidth all-optical 3×3 switch based on multimode interference structures

    NASA Astrophysics Data System (ADS)

    Le, Duy-Tien; Truong, Cao-Dung; Le, Trung-Thanh

    2017-03-01

    A high bandwidth all-optical 3×3 switch based on general interference multimode interference (GI-MMI) structure is proposed in this study. Two 3×3 multimode interference couplers are cascaded to realize an all-optical switch operating at both wavelengths of 1550 nm and 1310 nm. Two nonlinear directional couplers at two outer-arms of the structure are used as all-optical phase shifters to achieve all switching states and to control the switching states. Analytical expressions for switching operation using the transfer matrix method are presented. The beam propagation method (BPM) is used to design and optimize the whole structure. The optimal design of the all-optical phase shifters and 3×3 MMI couplers are carried out to reduce the switching power and loss.

  19. Noncosmological signal contributions to the COBE DMR anisotropy maps. [Differential Microwave Radiometer

    NASA Technical Reports Server (NTRS)

    Bennett, C. L.; Hinshaw, G.; Banday, A.; Kogut, A.; Wright, E. L.; Loewenstein, K.; Cheng, E. S.

    1993-01-01

    We examine the COBE Differential Microwave Radiometer (DMR) data for evidence of noncosmological source contributions. The DMR maps are cross-correlated with maps of rich clusters, extragalactic IRAS sources, HEAO 1 A-2 X-ray emission, and 5 GHz radio sources. We limit the rms contributions from these sources on a 7 deg angular scale to less than 10 micro-K (95 percent confidence level) in the DMR maps, although the LMC probably contributes about 50 micro-K to a limited region of the sky. Thus, our previous interpretation that the fluctuations in the COBE DMR data are most likely due to cosmic fluctuations at the surface of last scattering remains intact. The Comptonization parameter for hot electrons traced by rich clusters is limited to delta(y) less than 2 x 10 exp -6 (95 percent confidence level) averaged over the 7 deg DMR beam.

  20. Materials and devices for all-optical helicity-dependent switching

    NASA Astrophysics Data System (ADS)

    Salah El Hadri, Mohammed; Hehn, Michel; Malinowski, Grégory; Mangin, Stéphane

    2017-04-01

    Since the first observation of ultrafast demagnetization in Ni thin films by Beaurepaire et al 20 years ago, understanding the interaction between ultrashort laser pulses and magnetization has become a topic of huge interest. In 2007, an intriguing discovery related to ultrafast demagnetization was the observation of all-optical switching (AOS) of magnetization in ferrimagnetic GdFeCo alloy films using only femtosecond laser pulses. This review discusses the recent studies elucidating several key issues regarding the all-optical switching phenomenon. Although AOS had long been restricted to GdFeCo alloys, it turned out to be a more general phenomenon for a variety of ferrimagnetic as well as ferromagnetic materials. This discovery helped pave the way for the integration of all-optical writing in data storage industries. Nevertheless, theoretical models explaining the switching in GdFeCo alloy films do not appear to apply in the other materials, thus questioning the uniqueness of the microscopic origin of all-optical switching. By investigating the integration of all-optical switching in spintronic devices, two types of all-optical switching mechanism have been distinguished: a single-pulse heat-only switching in ferrimagnetic GdFeCo alloys, and a two regime helicity-dependent switching in both ferrimagnetic TbCo alloys and ferromagnetic Co/Pt multilayers. Another key issue discussed in this review is the necessary condition for the observation of all-optical switching. Many models have been proposed but are strongly challenged by the discovery of such switching in ferromagnets. A comprehensive investigation of the magnetic parameters governing all-optical switching demonstrate that its observation requires magnetic domains larger than the laser spot size during the cooling process; such a criterion is common for both ferri- and ferro-magnets. These investigations strongly improve our understanding and give intriguing insights into the rich physics of the ultrafast

  1. 160 Gb/s OFDM transmission utilizing an all-optical symbol generator based on PLC

    NASA Astrophysics Data System (ADS)

    Liang, Xiaojun; Qiao, Yaojun; Li, Wei; Mei, Junyao; Qin, Yi

    2009-11-01

    We demonstrate a 160 Gb/s orthogonal frequency division multiplexing (OFDM) system using an all-optical symbol generator based on planar light circuit (PLC) technology. Excellent bit error rate (BER) is observed after long-distance transmission. The proposed symbol generator fundamentally eliminates the processing speed limits introduced by electronics and is suitable for high integration, making it physically realizable to build high-speed all-optical OFDM systems with a large number of subcarriers.

  2. All-Optical Terahertz Optical Asymmetric Demultiplexer (toad) Based Binary Comparator:. a Proposal

    NASA Astrophysics Data System (ADS)

    Chattopadhyay, Tanay

    Comparator determines whether a number is greater than, equals to or less than another number. It plays a significant role in fast central processing unit in all-optical scheme. In all-optical scheme here 1-bit binary comparator is proposed and described by Terahertz Optical Asymmetric Demultiplexer (TOAD) based interferometric switch. Simulation result by Mathcad-7 is also given. Cascading technique of building up the n-bit binary comparator with this 1-bit comparator block is also proposed here.

  3. Magnetic induction tomography using an all-optical ⁸⁷Rb atomic magnetometer.

    PubMed

    Wickenbrock, Arne; Jurgilas, Sarunas; Dow, Albert; Marmugi, Luca; Renzoni, Ferruccio

    2014-11-15

    We demonstrate magnetic induction tomography (MIT) with an all-optical atomic magnetometer. Our instrument creates a conductivity map of conductive objects. Both the shape and size of the imaged samples compare very well with the actual shape and size. Given the potential of all-optical atomic magnetometers for miniaturization and extreme sensitivity, the proof-of-principle presented in this Letter opens up promising avenues in the development of instrumentation for MIT.

  4. Variable frequency microwave heating apparatus

    DOEpatents

    Bible, Don W.; Lauf, Robert J.; Johnson, Arvid C.; Thigpen, Larry T.

    1999-01-01

    A variable frequency microwave heating apparatus (10) designed to allow modulation of the frequency of the microwaves introduced into a multi-mode microwave cavity (34) for testing or other selected applications. The variable frequency microwave heating apparatus (10) includes a microwave signal generator (12) and a high-power microwave amplifier (20) or a high-power microwave oscillator (14). A power supply (22) is provided for operation of the high-power microwave oscillator (14) or microwave amplifier (20). A directional coupler (24) is provided for detecting the direction and amplitude of signals incident upon and reflected from the microwave cavity (34). A first power meter (30) is provided for measuring the power delivered to the microwave furnace (32). A second power meter (26) detects the magnitude of reflected power. Reflected power is dissipated in the reflected power load (28).

  5. Variable frequency microwave heating apparatus

    SciTech Connect

    Bible, D.W.; Lauf, R.J.; Johnson, A.C.; Thigpen, L.T.

    1999-10-05

    A variable frequency microwave heating apparatus (10) designed to allow modulation of the frequency of the microwaves introduced into a multi-mode microwave cavity (34) for testing or other selected applications. The variable frequency microwave heating apparatus (10) includes a microwave signal generator (12) and a high-power microwave amplifier (20) or a high-power microwave oscillator (14). A power supply (22) is provided for operation of the high-power microwave oscillator (14) or microwave amplifier (20). A directional coupler (24) is provided for detecting the direction and amplitude of signals incident upon and reflected from the microwave cavity (34). A first power meter (30) is provided for measuring the power delivered to the microwave furnace (32). A second power meter (26) detects the magnitude of reflected power. Reflected power is dissipated in the reflected power load (28).

  6. Study of mode locked fiber lasers and all-optical logic

    NASA Astrophysics Data System (ADS)

    Dong, Hao

    Mode locked fiber laser and all-optical logic technologies are building blocks for the construction of all-optical networks in the information era. This Ph.D dissertation investigates essential mechanism related to the mode locked lasers and all-optical logic such as the multiwavelength laser source, multiwavelength pulses, high-speed short pulse generation, clock recovery and all optical Boolean functions. First, a CW multiwavelength laser source oscillating in 75 wavelengths is proposed based on the semiconductor optical amplifier (SOA) enclosed in the fiber ring cavity, and the stability of the laser source will be investigated in detail. In the optical time division multiplexing (OTDM) system, it's of vital importance to generate optical pulses with narrow pulsewidth, high repetition rate, and long-term stability, towards this goal, an 80GHz short pulse train generation system is presented. A high speed clock recovery operation is also demonstrated based on the Mach-Zehnder (MZ) modulator; the conversion efficiency of the proposed clock recovery circuit is analyzed numerically. In addition, effective all-optical logic functions are also proposed to overcome a critical speed limit, Boolean OR, NOR, and AND functions are reported at the speed up to 80Gb/s using SOA based devices. These are the highest reported operating speed, at which the proposed all optical logic gates have been characterized.

  7. All-optical 4-bit binary to binary coded decimal converter with the help of semiconductor optical amplifier-assisted Sagnac switch

    NASA Astrophysics Data System (ADS)

    Bhattachryya, Arunava; Kumar Gayen, Dilip; Chattopadhyay, Tanay

    2013-04-01

    All-optical 4-bit binary to binary coded decimal (BCD) converter has been proposed and described, with the help of semiconductor optical amplifier (SOA)-assisted Sagnac interferometric switches in this manuscript. The paper describes all-optical conversion scheme using a set of all-optical switches. BCD is common in computer systems that display numeric values, especially in those consisting solely of digital logic with no microprocessor. In many personal computers, the basic input/output system (BIOS) keep the date and time in BCD format. The operations of the circuit are studied theoretically and analyzed through numerical simulations. The model accounts for the SOA small signal gain, line-width enhancement factor and carrier lifetime, the switching pulse energy and width, and the Sagnac loop asymmetry. By undertaking a detailed numerical simulation the influence of these key parameters on the metrics that determine the quality of switching is thoroughly investigated.

  8. Signal Detection Theory-Based Information Processing for the Detection of Breast Cancer at Microwave Frequencies

    DTIC Science & Technology

    2002-08-01

    the measurement noise, as well as the physical model of the forward scattered electric field. The Bayesian algorithms for the Uncertain Permittivity...received at multiple sensors. In this research project a tissue- model -based signal-detection theory approach for the detection of mammary tumors in the...oriented information processors. In this research project a tissue- model - based signal detection theory approach for the detection of mammary tumors in the

  9. External cavity based single mode Fabry-Pérot laser diode and its application towards all-optical digital circuits

    NASA Astrophysics Data System (ADS)

    Nakarmi, Bikash; Zhang, Xuping; Won, Yong Hyub

    2012-11-01

    We have proposed a novel approach of realizing all-optical logic gates and combinational circuit using external cavity based single mode Fabry-Pérot laser diodes (SMFP-LDs). Different techniques and critical parameters for injection locking the any one of the modes of SMFP-LDs are discussed. Taking consideration of wavelength detuning and input injected power, we have proposed and demonstrated multi-input injection locking, supporting beam injection locking with the conventional injection locking which are used for demonstrating different logic gates (NAND, AND, XNOR, XOR, NOT, NOR) and digital circuits (Half adder and Comparator). Since we have used SMFP-LDs, there is no requirement of additional probe beam and associated components as required by other optical technologies making the realization simple in configuration, cost effective and power efficient. Clear output waveforms, eye diagrams, risingfalling times and BER are presented to verify the proposed method. All-optical logic units and digital circuit are demonstrated at the data rate of 10 Gbps with the waveform of NRZ signal waveform and measured eye diagram and BER of the PRBS of 231-1 signal. The maximum power penalty among all demonstrated units is below 1.4 dB at the BER of 10-9.

  10. Nanoscale on-chip all-optical logic parity checker in integrated plasmonic circuits in optical communication range

    PubMed Central

    Wang, Feifan; Gong, Zibo; Hu, Xiaoyong; Yang, Xiaoyu; Yang, Hong; Gong, Qihuang

    2016-01-01

    The nanoscale chip-integrated all-optical logic parity checker is an essential core component for optical computing systems and ultrahigh-speed ultrawide-band information processing chips. Unfortunately, little experimental progress has been made in development of these devices to date because of material bottleneck limitations and a lack of effective realization mechanisms. Here, we report a simple and efficient strategy for direct realization of nanoscale chip-integrated all-optical logic parity checkers in integrated plasmonic circuits in the optical communication range. The proposed parity checker consists of two-level cascaded exclusive-OR (XOR) logic gates that are realized based on the linear interference of surface plasmon polaritons propagating in the plasmonic waveguides. The parity of the number of logic 1s in the incident four-bit logic signals is determined, and the output signal is given the logic state 0 for even parity (and 1 for odd parity). Compared with previous reports, the overall device feature size is reduced by more than two orders of magnitude, while ultralow energy consumption is maintained. This work raises the possibility of realization of large-scale integrated information processing chips based on integrated plasmonic circuits, and also provides a way to overcome the intrinsic limitations of serious surface plasmon polariton losses for on-chip integration applications. PMID:27073154

  11. Energy logistics in an all-optical adder based on a 1D porous silicon photonic crystal

    NASA Astrophysics Data System (ADS)

    Glushko, E. Ya.

    2011-09-01

    The ideology of a photonic crystal resonator covered with optically nonlinear layers is proposed for binary adder and logic gates of various kinds. The all-optical way to transform a physically added sequence of signals into the logical sequence with corresponding shift of digital units is based on the nonlinear band shift effect. In this work, the electromagnetic field structure for optically linear 1D porous silicon photonic crystal is investigated. The optical parameters of a 1D photonic crystal resonator built on layered porous silicon covered with a nonlinear layer are calculated for various nonlinear materials. An approximate design of an all-optical adder based on 1D porous silicon resonator is considered. The adder heating by powered optical pulses and energy distribution inside the device are analyzed and the problem solution with the use of special semitransparent redirecting mirrors is proposed. It was found that from the point of view of heating the R-scheme of signal processing is more optimal.

  12. Compact optical displacement sensing by detection of microwave signals generated from a monolithic passively mode-locked laser under feedback

    NASA Astrophysics Data System (ADS)

    Simos, Christos; Simos, Hercules; Nikas, Thomas; Syvridis, Dimitris

    2015-05-01

    A monolithic passively mode-locked laser is proposed as a compact optical sensor for displacements and vibrations of a reflecting object. The sensing principle relies on the change of the laser repetition frequency that is induced by optical feedback from the object under measurement. It has been previously observed that, when a semiconductor passively mode locked laser receives a sufficient level of optical feedback from an external reflecting surface it exhibits a repetition frequency that is no more determined by the mode-locking rule of the free-running operation but is imposed by the length of the external cavity. Therefore measurement of the resulting laser repetition frequency under self-injection permits the accurate and straightforward determination of the relative position of the reflecting object. The system has an inherent wireless capability since the repetition rate of the laser can be wirelessly detected by means of a simple antenna which captures the microwave signal generated by the saturable absorber and is emitted through the wiring of the laser. The sensor setup is very simple as it requires few optical components besides the laser itself. Furthermore, the deduction of the relative position of the reflecting object is straightforward and does not require any processing of the detected signal. The proposed sensor has a theoretical sub-wavelength resolution and its performance depends on the RF linewidth of the laser and the resolution of the repetition frequency measurement. Other physical parameters that induce phase changes of the external cavity could also be quantified.

  13. Silicon Photonics: All-Optical Devices for Linear and Nonlinear Applications

    NASA Astrophysics Data System (ADS)

    Driscoll, Jeffrey B.

    are shown to contribute no time-averaged momentum. Furthermore, the vectoral modal components, in conjunction with the tensoral nature of the third-order susceptibility of Si, lead to nonlinear properties which are dependent on waveguide orientation with respect to the Si parent crystal and the construction of the modal electric field components. This consideration is used to maximize effective nonlinearity and realize nonlinear Kerr gratings along specific waveguide trajectories. Tight optical confinement leads to a natural enhancement of the intrinsically large effective nonlinearty of Si waveguides, and in fact, the effective nonlinearty can be made to be almost 106 times greater in Si waveguides than that of standard single-mode fiber. Such a large nonlinearity motivates chip-scale all-optical signal processing techniques. Wavelength conversion by both four-wave-mixing (FWM) and cross-phase-modulation (XPM) will be discussed, including a technique that allows for enhanced broadband discrete FWM over arbitrary spectral spans by modulating both the linear and nonlinear waveguide properties through periodic changes in waveguide geometry. This quasi-phase-matching approach has very real applications towards connecting mature telecom sources detectors and components to other spectral regimes, including the mid-IR. Other signal processing techniques such as all-optical modulation format conversion via XPM will also be discussed. This thesis will conclude by looking at ways to extend the bandwidth capacity of Si waveguide interconnects on chip. As the number of processing cores continues to scale as a means for computational performance gains, on-chip link capacity will become an increasingly important issue. Metallic traces have severe limitations and are envisioned to eventually bow to integrated photonic links. The aggregate bandwidth supported by a single waveguide link will therefore become a crucial consideration as integrated photonics approaches the CPU. One way

  14. All-fibre photonic signal generator for attosecond timing and ultralow-noise microwave.

    PubMed

    Jung, Kwangyun; Kim, Jungwon

    2015-11-04

    High-impact frequency comb applications that are critically dependent on precise pulse timing (i.e., repetition rate) have recently emerged and include the synchronization of X-ray free-electron lasers, photonic analogue-to-digital conversion and photonic radar systems. These applications have used attosecond-level timing jitter of free-running mode-locked lasers on a fast time scale within ~100 μs. Maintaining attosecond-level absolute jitter over a significantly longer time scale can dramatically improve many high-precision comb applications. To date, ultrahigh quality-factor (Q) optical resonators have been used to achieve the highest-level repetition-rate stabilization of mode-locked lasers. However, ultrahigh-Q optical-resonator-based methods are often fragile, alignment sensitive and complex, which limits their widespread use. Here we demonstrate a fibre-delay line-based repetition-rate stabilization method that enables the all-fibre photonic generation of optical pulse trains with 980-as (20-fs) absolute r.m.s. timing jitter accumulated over 0.01 s (1 s). This simple approach is based on standard off-the-shelf fibre components and can therefore be readily used in various comb applications that require ultra-stable microwave frequency and attosecond optical timing.

  15. All-fibre photonic signal generator for attosecond timing and ultralow-noise microwave

    NASA Astrophysics Data System (ADS)

    Jung, Kwangyun; Kim, Jungwon

    2015-11-01

    High-impact frequency comb applications that are critically dependent on precise pulse timing (i.e., repetition rate) have recently emerged and include the synchronization of X-ray free-electron lasers, photonic analogue-to-digital conversion and photonic radar systems. These applications have used attosecond-level timing jitter of free-running mode-locked lasers on a fast time scale within ~100 μs. Maintaining attosecond-level absolute jitter over a significantly longer time scale can dramatically improve many high-precision comb applications. To date, ultrahigh quality-factor (Q) optical resonators have been used to achieve the highest-level repetition-rate stabilization of mode-locked lasers. However, ultrahigh-Q optical-resonator-based methods are often fragile, alignment sensitive and complex, which limits their widespread use. Here we demonstrate a fibre-delay line-based repetition-rate stabilization method that enables the all-fibre photonic generation of optical pulse trains with 980-as (20-fs) absolute r.m.s. timing jitter accumulated over 0.01 s (1 s). This simple approach is based on standard off-the-shelf fibre components and can therefore be readily used in various comb applications that require ultra-stable microwave frequency and attosecond optical timing.

  16. All-fibre photonic signal generator for attosecond timing and ultralow-noise microwave

    PubMed Central

    Jung, Kwangyun; Kim, Jungwon

    2015-01-01

    High-impact frequency comb applications that are critically dependent on precise pulse timing (i.e., repetition rate) have recently emerged and include the synchronization of X-ray free-electron lasers, photonic analogue-to-digital conversion and photonic radar systems. These applications have used attosecond-level timing jitter of free-running mode-locked lasers on a fast time scale within ~100 μs. Maintaining attosecond-level absolute jitter over a significantly longer time scale can dramatically improve many high-precision comb applications. To date, ultrahigh quality-factor (Q) optical resonators have been used to achieve the highest-level repetition-rate stabilization of mode-locked lasers. However, ultrahigh-Q optical-resonator-based methods are often fragile, alignment sensitive and complex, which limits their widespread use. Here we demonstrate a fibre-delay line-based repetition-rate stabilization method that enables the all-fibre photonic generation of optical pulse trains with 980-as (20-fs) absolute r.m.s. timing jitter accumulated over 0.01 s (1 s). This simple approach is based on standard off-the-shelf fibre components and can therefore be readily used in various comb applications that require ultra-stable microwave frequency and attosecond optical timing. PMID:26531777

  17. Microwave signal amplification and Pierce instability on radial electron flows in cylindrical and spherical diodes

    SciTech Connect

    Gnavi, G.; Gratton, F.T. )

    1994-11-01

    Linear space charge perturbations of focused electron beams flowing between cylindrical and spherical electrodes on convergent or divergent trajectories are studied, and the amplification of high-frequency signals when the flow is modulated at one electrode is computed. It is shown that divergent beams give the largest amplification effect. The instability of electron beams drifting through grounded grids (Pierce instability in cylindrical or spherical diodes) is also considered. The instability threshold occurs at higher critical currents when the curvature of the electrodes is large. Results for planar electrodes are recovered in the limit of zero curvature devices. Spherical configurations have better signal amplification and stability properties than similar planar or cylindrical systems.

  18. Diamond Radio Receiver: Nitrogen-Vacancy Centers as Fluorescent Transducers of Microwave Signals

    NASA Astrophysics Data System (ADS)

    Shao, Linbo; Zhang, Mian; Markham, Matthew; Edmonds, Andrew M.; Lončar, Marko

    2016-12-01

    We demonstrate a robust frequency-modulated radio receiver using electron-spin-dependent photoluminescence of nitrogen-vacancy centers in diamond. The carrier frequency of the frequency-modulated signal is in the 2.8-GHz range, determined by the zero-field splitting in the nitrogen-vacancy electronic ground state. The radio can be tuned over 300 MHz by applying an external dc magnetic field. We show the transmission of high-fidelity audio signals over a bandwidth of 91 kHz using the diamond radio. We demonstrate operating temperature of the radio as high as 350 ° C .

  19. Critical Performance Enhancement of Ultrahigh-Bandwidth Microwave Photonic Links through Nonlinear Photonic Signal Processing

    DTIC Science & Technology

    2013-04-11

    four-wave mixing (FWM) interaction such that in an amplifier-less link we are thermally noise limited after photodetection due to a low received...link with self-phase modulation based enhancement and balanced detection. optical signal. During this quarter we have constructed the sampling-based...photodetector. Furthermore, 8-dB of signal gain, a 3.6-dB improvement in OIP3, and a 3.1 -dB improvement in OIP2. the use of the balanced detector allows for

  20. Fast, high-fidelity, all-optical and dynamically-controlled polarization gate using room-temperature atomic vapor

    SciTech Connect

    Li, Runbing; Zhu, Chengjie; Deng, L.; Hagley, E. W.

    2014-10-20

    We demonstrate a fast, all-optical polarization gate in a room-temperature atomic medium. Using a Polarization-Selective-Kerr-Phase-Shift (PSKPS) technique, we selectively write a π phase shift to one circularly-polarized component of a linearly-polarized input signal field. The output signal field maintains its original strength but acquires a 90° linear polarization rotation, demonstrating fast, high-fidelity, dynamically-controlled polarization gate operation. The intensity of the polarization-switching field used in this PKSPK-based polarization gate operation is only 2 mW/cm{sup 2}, which would be equivalent to 0.5 nW of light power (λ = 800 nm) confined in a typical commercial photonic hollow-core fiber. This development opens a realm of possibilities for potential future extremely low light level telecommunication and information processing systems.

  1. Polarization insensitive all-optical up-conversion for ROF systems based on parallel pump FWM in a SOA.

    PubMed

    Lu, Jia; Dong, Ze; Cao, Zizheng; Chen, Lin; Wen, Shuangchun; Yu, Jianguo

    2009-04-27

    We have proposed and experimentally investigated polarization insensitive all-optical up-conversion for ROF system based on FWM in a semiconductor optical amplifier (SOA). The parallel pump is generated based on odd-order optical sidebands and carrier suppression using an external intensity modulator and a cascaded optical filter. Therefore, the two pumps are always parallel and phase locked, which makes system polarization insensitive. After FWM in a SOA and optical filtering, similar to single sideband (SSB) 40 GHz optical millimeter-wave is generated only using 10 GHz RF as local oscillator (LO). The receiver sensitivity at a BER of 10(-9) for the up-converted signals is -28.4 dBm. The power penalty for the up-converted downstream signals is smaller than 1 dBm after 20 km SSMF-28 transmission.

  2. Probing nonlinear magnetization dynamics in Fe/MgO(001) film by all optical pump-probe technique

    SciTech Connect

    He, Wei; Hu, Bo; Zhang, Xiang-Qun; Cheng, Zhao-Hua; Zhan, Qing-Feng

    2014-04-07

    An all-optical pump-probe technique has been employed to investigate the nonlinear magnetization dynamics of a 10 nm Fe/MgO(001) thin film in time domain. The magnetization precession was excited by pump-laser pulses and modulated by laser fluence variations. With increasing the laser fluence up to 7.1 mJ/cm{sup 2}, in addition to the uniform precession mode, a second harmonic signal was detected. The time evolution of the second harmonic signal was obtained in time-frequency domain. Based on the Landau-Lifshitz-Gilbert equation, the numerical simulation was performed to reproduce the observed the frequency doubling behaviors in Fe/MgO(001) film.

  3. Singular Value Decomposition-Based Modeling of Time Domain Signals in Broadband Microwave Spectroscopy

    NASA Astrophysics Data System (ADS)

    Minei, A. J.; Cooke, S. A.

    2013-06-01

    A singular value decomposition (SVD) signal processing method is newly applied to molecular free induction decays (FIDs) obtained using a time domain, broadband rotational spectrometer. It is demonstrated that for the strongest spectral transitions the SVD method can determine transition frequencies with a precision matching that of the fast Fourier transform method. Furthermore, the SVD-based analysis produces information concerning transition phase, amplitude, damping, and frequency for the strongest molecular signals. These parameters are shown as useful in regards to time-domain signal filtering. The computational expense of the SVD method is high and therefore this approach has the disadvantage that with our present computers the full molecular FID must be considerably truncated. The effects of FID truncation on the determined transition frequencies have been examined. Conversely, this truncation method illustrates that broadband spectra may be recovered from fragments as small as 1 % of the complete FID. The success of the SVD-based method is further examined in regards to weak signal detection, and frequency dependent detection. The pure rotational spectrum of 1H,1H,2H-perfluorocyclobutane is used for illustrative purposes in this study.

  4. Broadband Microwave Wireless Power Transfer for Weak-Signal and Multipath Environments

    NASA Technical Reports Server (NTRS)

    Barton, Richard J.

    2014-01-01

    In this paper, we study the potential benefits of using relatively broadband wireless power transmission WPT strategies in both weak-signal and multipath environments where traditional narrowband strategies can be very inefficient. The paper is primarily a theoretical and analytical treatment of the problem that attempts to derive results that are widely applicable to many different WPT applications, including space solar power SSP.

  5. Quaternary Galois field adder based all-optical multivalued logic circuits.

    PubMed

    Chattopadhyay, Tanay; Taraphdar, Chinmoy; Roy, Jitendra Nath

    2009-08-01

    Galois field (GF) algebraic expressions have been found to be promising choices for reversible and quantum implementation of multivalued logic. For the first time to our knowledge, we developed GF(4) adder multivalued (four valued) logic circuits in an all-optical domain. The principle and possibilities of an all-optical GF(4) adder circuit are described. The theoretical model is presented and verified through numerical simulation. The quaternary inverter, successor, clockwise cycle, and counterclockwise cycle gates are proposed with the help of the all-optical GF(4) adder circuit. In this scheme different quaternary logical states are represented by different polarized light. A terahertz optical asymmetric demultiplexer interferometric switch plays an important role in this scheme.

  6. All-optical flip-flop based on vertical cavity semiconductor optical amplifiers.

    PubMed

    Song, Deqiang; Gauss, Veronica; Zhang, Haijiang; Gross, Matthias; Wen, Pengyue; Esener, Sadik

    2007-10-15

    We report the operation of an all-optical set-reset (SR) flip-flop based on vertical cavity semiconductor optical amplifiers (VCSOAs). This flip-flop is cascadable, has low optical switching power (~10 microW), and has the potential to be integrated on a small footprint (~100 microm(2)). The flip-flop is composed of two cross-coupled electrically pumped VCSOA inverters and uses the principles of cross-gain modulation, polarization gain anisotropy, and highly nonlinear gain characteristics to achieve flip-flop functionality. We believe that, when integrated on chip, this type of all-optical flip-flop opens new prospects for implementing all-optical fast memories and timing regeneration circuits.

  7. All-optical virtual private network and ONUs communication in optical OFDM-based PON system.

    PubMed

    Zhang, Chongfu; Huang, Jian; Chen, Chen; Qiu, Kun

    2011-11-21

    We propose and demonstrate a novel scheme, which enables all-optical virtual private network (VPN) and all-optical optical network units (ONUs) inter-communications in optical orthogonal frequency-division multiplexing-based passive optical network (OFDM-PON) system using the subcarrier bands allocation for the first time (to our knowledge). We consider the intra-VPN and inter-VPN communications which correspond to two different cases: VPN communication among ONUs in one group and in different groups. The proposed scheme can provide the enhanced security and a more flexible configuration for VPN users compared to the VPN in WDM-PON or TDM-PON systems. The all-optical VPN and inter-ONU communications at 10-Gbit/s with 16 quadrature amplitude modulation (16 QAM) for the proposed optical OFDM-PON system are demonstrated. These results verify that the proposed scheme is feasible.

  8. Two types of all-optical magnetization switching mechanisms using femtosecond laser pulses

    NASA Astrophysics Data System (ADS)

    El Hadri, M. S.; Pirro, P.; Lambert, C.-H.; Petit-Watelot, S.; Quessab, Y.; Hehn, M.; Montaigne, F.; Malinowski, G.; Mangin, S.

    2016-08-01

    Using a time-dependent electrical investigation of the all-optical switching in ferrimagnetic and ferromagnetic Hall crosses via the anomalous Hall effect, intriguing insights into the rich physics underlying the all-optical switching are provided. We demonstrate that two different all-optical magnetization switching mechanisms can be distinguished; a "single pulse" switching for ferrimagnetic GdFeCo alloys, and a "two regimes" switching process for both ferrimagnetic TbCo alloys and ferromagnetic Pt/Co multilayers. We show that the latter takes place at two different time scales, and consists of a steplike helicity-independent multiple-domain formation within the first 1 ms followed by a helicity-dependent remagnetization on several tens of milliseconds.

  9. All-optical tunability of microdisk lasers via photo-adressable polyelectrolyte functionalization.

    PubMed

    Piegdon, K A; Lexow, M; Grundmeier, G; Kitzerow, H-S; Pärschke, K; Mergel, D; Reuter, D; Wieck, A D; Meier, C

    2012-03-12

    Photoactive materials are highly promising candidates for novel applications as they enable all-optical control of photonic devices. Photochromic molecules exhibit a reversible change of their dielectric function upon irradiation with light of proper wavelength. The trans- and cis-isomers of azobenzene exhibit different absorption properties due to the effect of the configuration on the polarizability of the molecule. Here, we introduce a novel molecular/semiconductor hybrid device which is fully tunable by all-optical means via the integration of a semiconductor microdisk into a photo-adressable polyelectrolyte material. We demonstrate that such polyelectrolyte superlattices can be used to tune semiconductor photonic resonators with high precision and without any significant degeneration of device performance. Moreover, we demonstrate an all-optically tunable laser based on this hybrid concept.

  10. Field trial of 160 Gb/s all-optical packet switching

    NASA Astrophysics Data System (ADS)

    Liu, Y.; Herrera, J.; Raz, O.; Tangdiongga, E.; Marti, J.; Ramos, F.; Maxwell, G.; Poustie, A.; Mulvad, H. C. H.; Hill, M. T.; de Waardt, H.; Khoe, G. D.; Koonen, A. M. J.; Dorren, H. J. S.

    2007-11-01

    We present the results of a transmission experiment, over 110 km of field installed fiber, for an all-optical 160 Gb/s packet switching system. The system uses in-band optical labels which are processed entirely in the optical domain using a narrow-band all-optical filter. The label decision information is stored by an optical flip-flop, which output controls a high-speed wavelength converter based on ultra-fast cross-phase modulation in a single semiconductor optical amplifier. The packet switched node is located in between two different fiber sections, each having a length of 54.3-km. The field installed fibers are located around the city of Eindhoven in the Netherlands. The results show how the all-optical switch can effectively route the packets based on the optical information and that such packets may be transmitted across the fiber with an acceptable penalty level.

  11. Direct generation of all-optical random numbers from optical pulse amplitude chaos.

    PubMed

    Li, Pu; Wang, Yun-Cai; Wang, An-Bang; Yang, Ling-Zhen; Zhang, Ming-Jiang; Zhang, Jian-Zhong

    2012-02-13

    We propose and theoretically demonstrate an all-optical method for directly generating all-optical random numbers from pulse amplitude chaos produced by a mode-locked fiber ring laser. Under an appropriate pump intensity, the mode-locked laser can experience a quasi-periodic route to chaos. Such a chaos consists of a stream of pulses with a fixed repetition frequency but random intensities. In this method, we do not require sampling procedure and external triggered clocks but directly quantize the chaotic pulses stream into random number sequence via an all-optical flip-flop. Moreover, our simulation results show that the pulse amplitude chaos has no periodicity and possesses a highly symmetric distribution of amplitude. Thus, in theory, the obtained random number sequence without post-processing has a high-quality randomness verified by industry-standard statistical tests.

  12. All-Optical Micro Motors Based on Moving Gratings in Photosensitive Media

    NASA Technical Reports Server (NTRS)

    Curley, M.; Sarkisov, S. S.; Fields, A.; Smith, C.; Kukhtarev, N.; Kulishov, M. B.; Adamovsky, Grigory

    2001-01-01

    An all-optical micromotor with a rotor driven by a traveling wave of surface deformation of a stator being in contact with the rotor is being studied. Instead of an ultrasonic wave produced by an electrically driven piezoelectric actuator as in ultrasonic motors, the wave is a result of a photo-induced surface deformation of a photosensitive material produced by an incident radiation. A thin piezoelectric polymer will deform more easily LiNbO3 or metal when irradiated with light. The type of photosensitive material studied are piezoelectric polymers with and without coatings for connecting electrodes. In order to be considered as a possible candidate for micromotors, the material should exhibit surface deformation produced by a laser beam of the order of 10 microns. This is compared to the deformations produced by static holographic gratings studied in photorefractive crystals of LiNbO3 using high vertical resolution surface profilometer Dektak 3 and surface interferometer WYKO. An experimental setup showing the oscillations has been developed. The setup uses a chopped beam from an Argon ion laser to produce the deformation while a probe beam is reflected by the thin film into a fiber which is then detected on an oscilloscope. A ramp voltage signal generator will drive the piezoelectric film in another experiment to determine the resonance of the film. A current is generated when light is incident upon the film and this current can be measured. The reverse process has already been demonstrated in other piezoelectric actuators. Changing voltage, polarity, and frequency of the signal can easily generate vibrations similar to those when light is incident on the film. This can be compared to the effects of laser interaction with light absorbing fluids such as solutions of 2,9,16,23-Tetrakis(phenylthio)-29H, 31 H-phthalocyanine in chlorobenzene in capillary tubes, The possibility of using a liquid with the piezoelectric film would be a novel idea for a micromotor since

  13. A study of high repetition rate pulse generation and all-optical add/drop multiplexing

    NASA Astrophysics Data System (ADS)

    Chen, Hongmin

    Ultra high-speed optical time-division-multiplexed (OTDM) transmission technologies are essential for the construction of ultra high-speed all-optical networks needed in the information era. In this Ph. D thesis dissertation, essential mechanisms associated with ultra high speed OTDM transmission systems, such as, high speed ultra short pulse generation, all optical demultiplexing and all optical add/drop multiplexing, have been studied. Both experimental demonstrations and numerical simulations have been performed. In order to realize high-speed optical TDM systems, high repetition rate, ultra short pulses are needed. A rational harmonic mode-locked ring fiber laser has been used to produce ultrashort pulses, the pulse jitter will be eliminated using a Phase-Locked-Loop (PLL), and the self-pulsation has been suppressed using a semiconductor optical amplifier (SOA). Sub pico-second pulses are very important for all optical sampling in the ultrahigh-speed OTDM transmission system. In this thesis, a two stage compression scheme utilizing the nonlinearity and dispersion of the optical fibers has been constructed and used to compress the gain switched DFB laser pulses. Also a nonlinear optical loop mirror has been constructed to suppress the wings associated with nonlinear compression. Pedestal free, transform-limited pulses with pulse widths in range of 0.2 to 0.4 ps have been generated. LiNbO3 modulators play a very important role in fiber optical communication systems. In this thesis, LiNbO3 modulators have been used to perform high repetition rate pulse generation, all optical demultiplexing and all optical add/drop for the TDM transmission system.

  14. Cascaded all-optical operations in a hybrid integrated 80-Gb/s logic circuit.

    PubMed

    LeGrange, J D; Dinu, M; Sochor, T; Bollond, P; Kasper, A; Cabot, S; Johnson, G S; Kang, I; Grant, A; Kay, J; Jaques, J

    2014-06-02

    We demonstrate logic functionalities in a high-speed all-optical logic circuit based on differential Mach-Zehnder interferometers with semiconductor optical amplifiers as the nonlinear optical elements. The circuit, implemented by hybrid integration of the semiconductor optical amplifiers on a planar lightwave circuit platform fabricated in silica glass, can be flexibly configured to realize a variety of Boolean logic gates. We present both simulations and experimental demonstrations of cascaded all-optical operations for 80-Gb/s on-off keyed data.

  15. All-optical stabilization of a soliton frequency comb in a crystalline microresonator.

    PubMed

    Jost, J D; Lucas, E; Herr, T; Lecaplain, C; Brasch, V; Pfeiffer, M H P; Kippenberg, T J

    2015-10-15

    We demonstrate the all-optical stabilization of a low-noise temporal soliton based microresonator based optical frequency comb in a crystalline resonator via a new technique to control the repetition rate. This is accomplished by thermally heating the microresonator with an additional probe laser coupled to an auxiliary optical resonator mode. The carrier-envelope offset frequency is controlled by stabilizing the pump laser frequency to a reference optical frequency comb. We analyze the stabilization by performing an out-of-loop comparison and measure the overlapping Allan deviation. This all-optical stabilization technique can prove useful as an actuator for self-referenced microresonator frequency combs.

  16. Controllable all-optical stochastic logic gates and their delay storages based on the cascaded VCSELs with optical-injection

    NASA Astrophysics Data System (ADS)

    Zhong, Dongzhou; Luo, Wei; Xu, Geliang

    2016-09-01

    Using the dynamical properties of the polarization bistability that depends on the detuning of the injected light, we propose a novel approach to implement reliable all-optical stochastic logic gates in the cascaded vertical cavity surface emitting lasers (VCSELs) with optical-injection. Here, two logic inputs are encoded in the detuning of the injected light from a tunable CW laser. The logic outputs are decoded from the two orthogonal polarization lights emitted from the optically injected VCSELs. For the same logic inputs, under electro-optic modulation, we perform various digital signal processing (NOT, AND, NAND, XOR, XNOR, OR, NOR) in the all-optical domain by controlling the logic operation of the applied electric field. Also we explore their delay storages by using the mechanism of the generalized chaotic synchronization. To quantify the reliabilities of these logic gates, we further demonstrate their success probabilities. Project supported by the National Natural Science Foundation of China (Grant No. 61475120) and the Innovative Projects in Guangdong Colleges and Universities, China (Grant Nos. 2014KTSCX134 and 2015KTSCX146).

  17. Utilization of Microwave Spectroscopy to Identify and Probe Reaction Dynamics of Hsno, a Crucial Biological Signaling Molecule

    NASA Astrophysics Data System (ADS)

    Nava, Matthew; Martin-Drumel, Marie-Aline; Stanton, John F.; Cummins, Christopher; McCarthy, Michael C.

    2016-06-01

    Thionitrous acid (HSNO), a potential key intermediate in biological signaling pathways, has been proposed to link NO and H2S biochemistries. Its existence and stability in vivo, however, remain controversial. By means of Fourier-transform microwave spectroscopy, we establish that HSNO is spontaneously formed in high concentration when NO and H2S gases are simply mixed at room temperature in the presence of metallic surfaces. Our measurements reveal that HSNO is formed with high efficiency by the reaction H2S and N2O3 to produce HSNO and HNO2, where N2O3 is a product of NO disproportionation. These studies also suggest that further reaction of HSNO with H2S may form HNO and HSSH. The length of the S--N bond has been derived to high precision from isotopic studies, and is found to be unusually long, 1.84 Å -- the longest S--N bond reported to date for an SNO compound. The present structural and reactivity investigations of this elusive molecule provide a firm fundation to better understand its physiological chemistry and propensity to undergo S--N bond homolysis in vivo.

  18. Effectiveness of phase-conjugated twin waves on fiber nonlinearity in spatially multiplexed all-optical OFDM system

    NASA Astrophysics Data System (ADS)

    Hmood, Jassim K.; Noordin, Kamarul A.; Harun, Sulaiman W.

    2016-07-01

    In this paper, we investigate the effectiveness of using phase-conjugated twin waves (PCTWs) technique to mitigate fiber nonlinear impairments in spatially multiplexed all-optical orthogonal frequency division multiplexing (AO-OFDM) systems. In this technique, AO-OFDM signal and its phase-conjugated copy are directly transmitted through two identical fiber links. At the receiver, the two signals are coherently superimposed to cancel the phase noise and to enhance signal-to-noise ratio (SNR). To show the effectiveness of proposed technique, a spatially multiplexed AO-OFDM system is demonstrated by numerical simulation. AO-OFDM signal and its phase conjugated copy are optically generated by using optical coupler-based inverse fast Fourier transform (OIFFT)/fast Fourier transform (OFFT). The generated signal includes 29 subcarriers where each subcarrier is modulated by 4-quadrature amplitude modulation (4QAM) format at a symbol rate of 25 Gsymbol/s. The results reveal that transmission performance is considerably improved where the transmission distance of the proposed system is increased by ∼45% as compared to that of original system without PCTWs technique.

  19. All optical discrete Fourier transform processor for 100 Gbps OFDM transmission.

    PubMed

    Lee, Kyusang; Thai, Chan T D; Rhee, June-Koo Kevin

    2008-03-17

    Optical orthogonal frequency division multiplex (OFDM) symbol generation by all-optical discrete Fourier transform (DFT) is proposed and investigated for 100-Gbps transmission performance. We discuss a design example for a 4x25Gbps OFDM transmission system and its performance comparison with that for a 100-Gbps single-channel return-to-zero data transmission in an optically amplified system.

  20. Magnetic induction measurements using an all-optical {sup 87}Rb atomic magnetometer

    SciTech Connect

    Wickenbrock, Arne; Tricot, François; Renzoni, Ferruccio

    2013-12-09

    In this work we propose, and experimentally demonstrate, the use of a self-oscillating all-optical atomic magnetometer for magnetic induction measurements. Given the potential for miniaturization of atomic magnetometers, and their extreme sensitivity, the present work shows that atomic magnetometers may play a key role in the development of instrumentation for magnetic induction tomography.

  1. Integration of photonic nanojets and semiconductor nanoparticles for enhanced all-optical switching

    PubMed Central

    Born, Brandon; Krupa, Jeffrey D. A.; Geoffroy-Gagnon, Simon; Holzman, Jonathan F.

    2015-01-01

    All-optical switching is the foundation of emerging all-optical (terabit-per-second) networks and processors. All-optical switching has attracted considerable attention, but it must ultimately support operation with femtojoule switching energies and femtosecond switching times to be effective. Here we introduce an all-optical switch architecture in the form of a dielectric sphere that focuses a high-intensity photonic nanojet into a peripheral coating of semiconductor nanoparticles. Milli-scale spheres coated with Si and SiC nanoparticles yield switching energies of 200 and 100 fJ with switching times of 10 ps and 350 fs, respectively. Micro-scale spheres coated with Si and SiC nanoparticles yield switching energies of 1 pJ and 20 fJ with switching times of 2 ps and 270 fs, respectively. We show that femtojoule switching energies are enabled by localized photoinjection from the photonic nanojets and that femtosecond switching times are enabled by localized recombination within the semiconductor nanoparticles. PMID:26314911

  2. Polarization encoded all-optical quaternary R-S flip-flop using binary latch

    NASA Astrophysics Data System (ADS)

    Chattopadhyay, Tanay; Roy, Jitendra Nath; Chakraborty, Ajoy Kumar

    2009-04-01

    The developments of different multi-valued logic (MVL) systems have received considerable interests in recent years all over the world. In electronics, efforts have already been made to incorporate multi-valued system in logic and arithmetic data processing. But, very little efforts have been given in realization of MVL with optics. In this paper we present novel designs of certain all-optical circuits that can be used for realizing multi-valued logic functions. Polarization encoded all-optical quaternary (4-valued) R-S flip-flop is proposed and described. Two key circuits (all-optical encoder/decoder and a binary latch) are designed first. They are used to realize quaternary flip-flop in all-optical domain. Here the different quaternary logical states are represented by different polarized state of light. Terahertz Optical Asymmetric Demultiplexer (TOAD) based interferometric switch can take an important role. Computer simulation result confirming described methods and conclusion are given in this paper.

  3. Integration of photonic nanojets and semiconductor nanoparticles for enhanced all-optical switching

    NASA Astrophysics Data System (ADS)

    Born, Brandon; Krupa, Jeffrey D. A.; Geoffroy-Gagnon, Simon; Holzman, Jonathan F.

    2015-08-01

    All-optical switching is the foundation of emerging all-optical (terabit-per-second) networks and processors. All-optical switching has attracted considerable attention, but it must ultimately support operation with femtojoule switching energies and femtosecond switching times to be effective. Here we introduce an all-optical switch architecture in the form of a dielectric sphere that focuses a high-intensity photonic nanojet into a peripheral coating of semiconductor nanoparticles. Milli-scale spheres coated with Si and SiC nanoparticles yield switching energies of 200 and 100 fJ with switching times of 10 ps and 350 fs, respectively. Micro-scale spheres coated with Si and SiC nanoparticles yield switching energies of 1 pJ and 20 fJ with switching times of 2 ps and 270 fs, respectively. We show that femtojoule switching energies are enabled by localized photoinjection from the photonic nanojets and that femtosecond switching times are enabled by localized recombination within the semiconductor nanoparticles.

  4. Integration of photonic nanojets and semiconductor nanoparticles for enhanced all-optical switching.

    PubMed

    Born, Brandon; Krupa, Jeffrey D A; Geoffroy-Gagnon, Simon; Holzman, Jonathan F

    2015-08-28

    All-optical switching is the foundation of emerging all-optical (terabit-per-second) networks and processors. All-optical switching has attracted considerable attention, but it must ultimately support operation with femtojoule switching energies and femtosecond switching times to be effective. Here we introduce an all-optical switch architecture in the form of a dielectric sphere that focuses a high-intensity photonic nanojet into a peripheral coating of semiconductor nanoparticles. Milli-scale spheres coated with Si and SiC nanoparticles yield switching energies of 200 and 100 fJ with switching times of 10 ps and 350 fs, respectively. Micro-scale spheres coated with Si and SiC nanoparticles yield switching energies of 1 pJ and 20 fJ with switching times of 2 ps and 270 fs, respectively. We show that femtojoule switching energies are enabled by localized photoinjection from the photonic nanojets and that femtosecond switching times are enabled by localized recombination within the semiconductor nanoparticles.

  5. A New All-Optical Imaging Scheme based on QWIP technology

    NASA Astrophysics Data System (ADS)

    Zeng, Debing; Chen, Gang; Martini, Rainer

    2006-03-01

    Infrared imaging applications have gained increasing interest over the recent decades due to favorable light propagation, night imaging as well as chemical sensing applications. However, the scalability of the existing techniques towards high resolution in the multi-megapixel range is one of the major challenges in today's IR imaging technologies. Here we present an alternative solution using an all-optical wavelength conversion scheme. QWIP has been successfully proven their potential in IR imaging applications. Yet the fundamental conversion process from IR light to electric current has been one of the major restrictions in such system. To overcome this problem we propose the use of an all-optical conversion scheme, which utilizes an interband resonant optical NIR beam to probe the electrical population of the QW structure. In this methodology the incident MIR radiation changes the occupation of the QWs, which in turn influences the NIR transmission. Hence the irradiated MIR images can be probed by spatially resolved measurement of the NIR transmission, as has been demonstrated by Nada et al. for all-optical switching purposes. In this talk we present an implementation scheme of the all-optical QWIP readout technique together with theoretical calculations of the sensitivity of the proposed device and its temperature dependence. First experimental results will be presented also. The Authors thankfully acknowledge financial support by US Army, Picatinny Arsenal.

  6. Elastic all-optical multi-hop interconnection in data centers with adaptive spectrum allocation

    NASA Astrophysics Data System (ADS)

    Hong, Yuanyuan; Hong, Xuezhi; Chen, Jiajia; He, Sailing

    2017-01-01

    In this paper, a novel flex-grid all-optical interconnect scheme that supports transparent multi-hop connections in data centers is proposed. An inter-rack all-optical multi-hop connection is realized with an optical loop employed at flex-grid wavelength selective switches (WSSs) in an intermediate rack rather than by relaying through optical-electric-optical (O-E-O) conversions. Compared with the conventional O-E-O based approach, the proposed all-optical scheme is able to off-load the traffic at intermediate racks, leading to a reduction of the power consumption and cost. The transmission performance of the proposed flex-grid multi-hop all-optical interconnect scheme with various modulation formats, including both coherently detected and directly detected approaches, are investigated by Monte-Carlo simulations. To enhance the spectrum efficiency (SE), number-of-hop adaptive bandwidth allocation is introduced. Numerical results show that the SE can be improved by up to 33.3% at 40 Gbps, and by up to 25% at 100 Gbps. The impact of parameters, such as targeted bit error rate (BER) level and insertion loss of components, on the transmission performance of the proposed approach are also explored. The results show that the maximum SE improvement of the adaptive approach over the non-adaptive one is enhanced with the decrease of the targeted BER levels and the component insertion loss.

  7. Analysis of all-optically tunable functionalities in subwavelength periodic structures by the Fourier modal method

    NASA Astrophysics Data System (ADS)

    Bej, Subhajit; Tervo, Jani; Francés, Jorge; Svirko, Yuri P.; Turunen, Jari

    2016-05-01

    We propose the nonlinear Fourier Modal Method (FMM) [J. Opt. Soc. Am. B 31, 2371 (2014)] as a convenient and versatile numerical tool for the design and analysis of grating based next generation all-optical devices. Here, we include several numerical examples where the FMM is used to simulate all-optically tunable functionalities in sub-wavelength periodic structures. At first, we numerically investigate a 1-D periodic nonlinear binary grating with amorphous TiO2. We plot the diffraction efficiency in the transmitted orders against the structure depth for normally incident plane wave. Change in diffraction efficiencies for different incident field amplitudes are evident from the plots. We verify the accuracy of our implementation by comparing our results with the results obtained with the nonlinear Split Field-Finite Difference Time Domain (SF-FDTD) method. Next we repeat the same experiment with vertically standing amorphous Titanium dioxide (TiO2) nanowire arrays grown on top of quartz which are periodic in two mutually perpendicular directions and examine the efficiencies in the direct transmitted light for different incident field amplitudes. Our third example includes analysis of a form birefringent linear grating with Kerr medium. With FMM we demonstrate that the birefringence of such a structure can be tuned by all-optical means. As a final example, we design a narrow band Guided Mode Resonance Filter (GMRF). Numerical experiments based on the nonlinear FMM reveal that the spectral tunability of such a filter can be obtained by all-optical means.

  8. Variable frequency microwave furnace system

    DOEpatents

    Bible, Don W.; Lauf, Robert J.

    1994-01-01

    A variable frequency microwave furnace system (10) designed to allow modulation of the frequency of the microwaves introduced into a furnace cavity (34) for testing or other selected applications. The variable frequency microwave furnace system (10) includes a microwave signal generator (12) or microwave voltage-controlled oscillator (14) for generating a low-power microwave signal for input to the microwave furnace. A first amplifier (18) may be provided to amplify the magnitude of the signal output from the microwave signal generator (12) or the microwave voltage-controlled oscillator (14). A second amplifier (20) is provided for processing the signal output by the first amplifier (18). The second amplifier (20) outputs the microwave signal input to the furnace cavity (34). In the preferred embodiment, the second amplifier (20) is a traveling-wave tube (TWT). A power supply (22) is provided for operation of the second amplifier (20). A directional coupler (24) is provided for detecting the direction of a signal and further directing the signal depending on the detected direction. A first power meter (30) is provided for measuring the power delivered to the microwave furnace (32). A second power meter (26) detects the magnitude of reflected power. Reflected power is dissipated in the reflected power load (28).

  9. Variable frequency microwave furnace system

    DOEpatents

    Bible, D.W.; Lauf, R.J.

    1994-06-14

    A variable frequency microwave furnace system designed to allow modulation of the frequency of the microwaves introduced into a furnace cavity for testing or other selected applications. The variable frequency microwave furnace system includes a microwave signal generator or microwave voltage-controlled oscillator for generating a low-power microwave signal for input to the microwave furnace. A first amplifier may be provided to amplify the magnitude of the signal output from the microwave signal generator or the microwave voltage-controlled oscillator. A second amplifier is provided for processing the signal output by the first amplifier. The second amplifier outputs the microwave signal input to the furnace cavity. In the preferred embodiment, the second amplifier is a traveling-wave tube (TWT). A power supply is provided for operation of the second amplifier. A directional coupler is provided for detecting the direction of a signal and further directing the signal depending on the detected direction. A first power meter is provided for measuring the power delivered to the microwave furnace. A second power meter detects the magnitude of reflected power. Reflected power is dissipated in the reflected power load. 5 figs.

  10. Routing and wavelength assignment based on normalized resource and constraints for all-optical network

    NASA Astrophysics Data System (ADS)

    Joo, Seong-Soon; Nam, Hyun-Soon; Lim, Chang-Kyu

    2003-08-01

    With the rapid growth of the Optical Internet, high capacity pipes is finally destined to support end-to-end IP on the WDM optical network. Newly launched 2D MEMS optical switching module in the market supports that expectations of upcoming a transparent optical cross-connect in the network have encouraged the field applicable research on establishing real all-optical transparent network. To open up a customer-driven bandwidth services, design of the optical transport network becomes more challenging task in terms of optimal network resource usage. This paper presents a practical approach to finding a route and wavelength assignment for wavelength routed all-optical network, which has λ-plane OXC switches and wavelength converters, and supports that optical paths are randomly set up and released by dynamic wavelength provisioning to create bandwidth between end users with timescales on the order of seconds or milliseconds. We suggest three constraints to make the RWA problem become more practical one on deployment for wavelength routed all-optical network in network view: limitation on maximum hop of a route within bearable optical network impairments, limitation on minimum hops to travel before converting a wavelength, and limitation on calculation time to find all routes for connections requested at once. We design the NRCD (Normalized Resource and Constraints for All-Optical Network RWA Design) algorithm for the Tera OXC: network resource for a route is calculated by the number of internal switching paths established in each OXC nodes on the route, and is normalized by ratio of number of paths established and number of paths equipped in a node. We show that it fits for the RWA algorithm of the wavelength routed all-optical network through real experiments on the distributed objects platform.

  11. Simultaneous demonstration on all-optical digital encoder and comparator at 40 Gb/s with semiconductor optical amplifiers.

    PubMed

    Wang, Yang; Zhang, Xinliang; Dong, Jianji; Huang, Dexiu

    2007-11-12

    We proposed and experimental demonstrated all-optical two line-four line encoder and two bit-wise comparator of RZ data streams at 40Gb/s based on cross gain modulation (XGM) and four wave mixing (FWM) in three parallel SOAs. Five logic functions for digital encoder and comparator between two signals A and B: AB, AB, AB, AB and AOmicronB, were achieved simultaneously. The first three optical logics are realized based on XGM in SOAs, the fourth is realized with FWM, and the fifth is the mixing result of the first and the fourth. A detuning filter is employed to improve the output performance. The output extinction ratio (ER) for the XGM operation is above 10dB, and the ER for FWM operation is around 8 dB. Wide and clear eye patterns for the five logic outputs can be observed.

  12. All-optical simultaneous phase and amplitude regenerator based on a modified Mach-Zehnder interferometric phase sensitive amplifier

    NASA Astrophysics Data System (ADS)

    Wang, Hongxiang; Li, Fengshuo; Ji, Yuefeng

    2017-02-01

    A modified Mach-Zehnder interferometric phase sensitive amplifier (MMZI-PSA) configuration is proposed and simulated, which combined the four-wave mixing phase-sensitive amplifier (FWM-PSA) with the fiber interference phase-sensitive amplifier (FI-PSA). This modified scheme for an all-optical communication system can not only eliminate phase noise, but also reduce additional amplitude noise, reducing intrinsic amplitude noise and suppressing phase-to-amplitude noise conversion tremendously. Compared with the traditional FWM-PSA configuration, the proposed configuration can obtain higher gain, as well as reduce bit-error rate (BER) and error vector magnitude (EVM). The simulation results suggest that MMZI-PSA can effectively regenerate QPSK signals and obtain 6.9-dB gain. Furthermore, it can reduce BER to 3.98×10-6 and reduce EVM to 22%, which improves system noise tolerance.

  13. Automated measurement of the bit-error rate as a function of signal-to-noise ratio for microwave communications systems

    NASA Technical Reports Server (NTRS)

    Kerczewski, Robert J.; Daugherty, Elaine S.; Kramarchuk, Ihor

    1987-01-01

    The performance of microwave systems and components for digital data transmission can be characterized by a plot of the bit-error rate as a function of the signal to noise ratio (or E sub b/E sub o). Methods for the efficient automated measurement of bit-error rates and signal-to-noise ratios, developed at NASA Lewis Research Center, are described. Noise measurement considerations and time requirements for measurement accuracy, as well as computer control and data processing methods, are discussed.

  14. All-optical logic gate based on transient grating from disperse red 1 doped organic-inorganic hybrid films with an improved figure of merit

    SciTech Connect

    Gao, Tianxi; Que, Wenxiu Shao, Jinyou; Wang, Yushu

    2015-10-21

    Azobenzene dyes have large refractive index near their main resonance, but the poor figure of merit (FOM) limits their potential for all-optical applications. To improve this situation, disperse red 1 (DR1) molecules were dispersed in a sol-gel germanium/Ormosil organic-inorganic hybrid matrix. Z-scan measurement results showed a good compatibility between the dopant and the matrix, and also, an improved FOM was obtained as compared to the DR1/polymer films reported previously. To demonstrate the all-optical signal processing effect, a cw Nd:YAG laser emitting at 532 nm and a He-Ne laser emitting at 632.8 nm were used as pump and probe beams, respectively. DR1 acts as an initiator of the photo-induced transient holographic grating, which is attributed to the trans-cis-trans photoisomerization. Thus, a three inputs AND all-optical logic gate was achieved by using choppers with different frequencies. The detailed mechanism of operation is discussed. These results indicate that the DR1 doped germanium/Ormosil organic-inorganic hybrid film with an improved FOM has a great potential in all-optical devices around its main resonance.

  15. Characterization of a Broadband All-Optical Ultrasound Transducer—From Optical and Acoustical Properties to Imaging

    PubMed Central

    Hou, Yang; Kim, Jin-Sung; Huang, Sheng-Wen; Ashkenazi, Shai; Guo, L. Jay; O’Donnell, Matthew

    2009-01-01

    A broadband all-optical ultrasound transducer has been designed, fabricated, and evaluated for high-frequency ultrasound imaging. The device consists of a 2-D gold nanostructure imprinted on top of a glass substrate, followed by a 3 μm PDMS layer and a 30 nm gold layer. A laser pulse at the resonance wavelength of the gold nanostructure is focused onto the surface for ultrasound generation, while the gold nanostructure, together with the 30 nm thick gold layer and the PDMS layer in between, forms an etalon for ultrasound detection, which uses a CW laser at a wavelength far from resonance as the probing beam. The center frequency of a pulse-echo signal recorded in the far field of the transducer is 40 MHz with -6 dB bandwidth of 57 MHz. The signal to noise ratio (SNR) from a 70 μm diameter transmit element combined with a 20 μm diameter receive element probing a near perfect reflector positioned 1.5 mm from the transducer surface is more than 10 dB and has the potential to be improved by at least another 40 dB. A high-frequency ultrasound array has been emulated using multiple measurements from the transducer while mechanically scanning an imaging target. Characterization of the device’s optical and acoustical properties, as well as preliminary imaging results, strongly suggest that all-optical ultrasound transducers can be used to build high-frequency arrays for real-time high-resolution ultrasound imaging. PMID:18986929

  16. All-optical scanhead for ultrasound and photoacoustic imaging—Imaging mode switching by dichroic filtering☆

    PubMed Central

    Hsieh, Bao-Yu; Chen, Sung-Liang; Ling, Tao; Guo, L. Jay; Li, Pai-Chi

    2014-01-01

    Ultrasound (US) and photoacoustic (PA) multimodality imaging has the advantage of combining good acoustic resolution with high optical contrast. The use of an all-optical scanhead for both imaging modalities can simplify integration of the two systems and miniaturize the imaging scanhead. Herein we propose and demonstrate an all-optical US/PA scanhead using a thin plate for optoacoustic generation in US imaging, a polymer microring resonator for acoustic detection, and a dichroic filter to switch between the two imaging modes by changing the laser wavelength. A synthetic-aperture focusing technique is used to improve the resolution and contrast. Phantom images demonstrate the feasibility of this design, and show that axial and lateral resolutions of 125 μm and 2.52°, respectively, are possible. PMID:25302154

  17. Ultrafast, broadband, and configurable midinfrared all-optical switching in nonlinear graphene plasmonic waveguides

    NASA Astrophysics Data System (ADS)

    Ooi, Kelvin J. A.; Cheng, J. L.; Sipe, J. E.; Ang, L. K.; Tan, Dawn T. H.

    2016-07-01

    Graphene plasmonics provides a unique and excellent platform for nonlinear all-optical switching, owing to its high nonlinear conductivity and tight optical confinement. In this paper, we show that impressive switching performance on graphene plasmonic waveguides could be obtained for both phase and extinction modulations at sub-MW/cm2 optical pump intensities. Additionally, we find that the large surface-induced nonlinearity enhancement that comes from the tight confinement effect can potentially drive the propagating plasmon pump power down to the pW range. The graphene plasmonic waveguides have highly configurable Fermi-levels through electrostatic-gating, allowing for versatility in device design and a broadband optical response. The high capabilities of nonlinear graphene plasmonics would eventually pave the way for the adoption of the graphene plasmonics platform in future all-optical nanocircuitry.

  18. Invited Article: All-optical multichannel logic based on coherent perfect absorption in a plasmonic metamaterial

    NASA Astrophysics Data System (ADS)

    Papaioannou, Maria; Plum, Eric; Valente, João; Rogers, Edward T. F.; Zheludev, Nikolay I.

    2016-12-01

    The exponential growth of telecommunications bandwidth will require next generation optical networks, where multiple spatial information channels will be transmitted in parallel. To realise the full potential of parallel optical data channels, fast and scalable multichannel solutions for processing of optical data are of paramount importance. Established solutions based on the nonlinear wave interaction in photorefractive materials are slow. Here we experimentally demonstrate all-optical logical operations between pairs of simulated spatially multiplexed information channels using the coherent interaction of light with light on a plasmonic metamaterial. The approach is suitable for fiber implementation and—in principle—operates with diffraction-limited spatial resolution, 100 THz bandwidth, and arbitrarily low intensities, thus promising ultrafast, low-power solutions for all-optical parallel data processing.

  19. Ultralow-light-level all-optical transistor in rubidium vapor

    SciTech Connect

    Jing, Jietai Zhou, Zhifan; Liu, Cunjin; Qin, Zhongzhong; Fang, Yami; Zhou, Jun; Zhang, Weiping

    2014-04-14

    An all-optical transistor (AOT) is a device in which one light beam can efficiently manipulate another. It is the foundational component of an all-optical communication network. An AOT that can operate at ultralow light levels is especially attractive for its potential application in the quantum information field. Here, we demonstrate an AOT driven by a weak light beam with an energy density of 2.5 × 10{sup −5} photons/(λ{sup 2}/2π) (corresponding to 6  yJ/(λ{sup 2}/2π) and about 800 total photons) using the double-Λ four-wave mixing process in hot rubidium vapor. This makes it a promising candidate for ultralow-light-level optical communication and quantum information science.

  20. Cascadable all-optical inverter based on a nonlinear vertical-cavity semiconductor optical amplifier.

    PubMed

    Zhang, Haijiang; Wen, Pengyue; Esener, Sadik

    2007-07-01

    We report, for the first time to our knowledge, the operation of a cascadable, low-optical-switching-power(~10 microW) small-area (~100 microm(2)) high-speed (80 ps fall time) all-optical inverter. This inverter employs cross-gain modulation, polarization gain anisotropy, and highly nonlinear gain characteristics of an electrically pumped vertical-cavity semiconductor optical amplifier (VCSOA). The measured transfer characteristics of such an optical inverter resemble those of standard electronic metal-oxide semiconductor field-effect transistor-based inverters exhibiting high noise margin and high extinction ratio (~9.3 dB), making VCSOAs an ideal building block for all-optical logic and memory.

  1. All-optical repetition rate multiplication of pseudorandom bit sequences based on cascaded TOADs

    NASA Astrophysics Data System (ADS)

    Sun, Zhenchao; Wang, Zhi; Wu, Chongqing; Wang, Fu; Li, Qiang

    2016-03-01

    A scheme for all-optical repetition rate multiplication of pseudorandom bit sequences (PRBS) is demonstrated with all-optical wavelength conversion and optical logic gate 'OR' based on cascaded Tera-Hertz Optical Asymmetric Demultiplexers (TOADs). Its feasibility is verified by multiplication experiments from 500 Mb/s to 4 Gb/s for 23-1 PRBS and from 1 Gb/s to 4 Gb/s for 27-1 PRBS. This scheme can be employed for rate multiplication for much longer cycle PRBS at much higher bit rate over 40 Gb/s when the time-delay, the loss and the dispersion of the optical delay line are all precisely managed. The upper limit of bit rate will be restricted by the recovery time of semiconductor optical amplifier (SOA) finally.

  2. 20Gbit/s all-optical logic OR in terahertz optical asymmetric demultiplexer (TOAD)

    NASA Astrophysics Data System (ADS)

    Yan, Yumei; Wu, Jian; Lin, Jintong

    2005-01-01

    A scheme for all-optical logic OR based on transparent teraherz optical asymmetric demultiplexer (transparent-TOAD) is proposed in this paper. In the transparent-TOAD, the SOA is biased at transparency and the gain recovery time determined by the intraband effect has the value of only a few picoseconds. Numerical analysis shows that the switching window of the transparent-TOAD is only about 0.54ps and the potential for ultrahigh speed all-optical logic processing is shown. Numerical demonstration is performed for 4-bit and 16-bit logic OR at 20Gbit/s. The results coincide with the OR truth table, showing high extinction ratio and no pattern dependency. Detailed analysis is carried out on the performance of the logic OR scheme.

  3. All-optical pseudorandom binary sequence generator with TOAD-based D flip-flops

    NASA Astrophysics Data System (ADS)

    Zoiros, K. E.; Das, M. K.; Gayen, D. K.; Maity, H. K.; Chattopadhyay, T.; Roy, J. N.

    2011-09-01

    An all-optical pseudo random binary sequence (PRBS) generator is designed using serially interconnected discrete Terahertz Optical Asymmetric Demultiplexer (TOAD)-based D flip-flops in a configuration exactly like the standard electronic setup. The performance of the circuit is evaluated through numerical simulation, which confirms its feasibility in terms of the choice of the critical parameters. The proposed scheme has been theoretically demonstrated for a 3-bit and 7-bit degree PRBS but can be extended to higher order by means of additional TOAD-based D flip-flops. Thus it can constitute an efficient solution for implementing all-optically a PRBS in an affordable, controllable and realistic manner.

  4. Ultrafast All-Optical Switching with Magnetic Resonances in Nonlinear Dielectric Nanostructures.

    PubMed

    Shcherbakov, Maxim R; Vabishchevich, Polina P; Shorokhov, Alexander S; Chong, Katie E; Choi, Duk-Yong; Staude, Isabelle; Miroshnichenko, Andrey E; Neshev, Dragomir N; Fedyanin, Andrey A; Kivshar, Yuri S

    2015-10-14

    We demonstrate experimentally ultrafast all-optical switching in subwavelength nonlinear dielectric nanostructures exhibiting localized magnetic Mie resonances. We employ amorphous silicon nanodisks to achieve strong self-modulation of femtosecond pulses with a depth of 60% at picojoule-per-disk pump energies. In the pump-probe measurements, we reveal that switching in the nanodisks can be governed by pulse-limited 65 fs-long two-photon absorption being enhanced by a factor of 80 with respect to the unstructured silicon film. We also show that undesirable free-carrier effects can be suppressed by a proper spectral positioning of the magnetic resonance, making such a structure the fastest all-optical switch operating at the nanoscale.

  5. All-optical photoacoustic microscopy based on plasmonic detection of broadband ultrasound

    NASA Astrophysics Data System (ADS)

    Wang, Tianxiong; Cao, Rui; Ning, Bo; Dixon, Adam J.; Hossack, John A.; Klibanov, Alexander L.; Zhou, Qifa; Wang, Anbo; Hu, Song

    2015-10-01

    We report on an implementation of all-optical photoacoustic microscopy (PAM), which capitalizes on the effect of surface plasmon resonance (SPR) for optical detection of ultrasound. The SPR sensor in our all-optical PAM shows, experimentally, a linear response to the acoustic pressure from 5.2 kPa to 2.1 MPa, an ultra-flat frequency response (±0.7 dB) from 680 kHz to 126 MHz, and a noise-equivalent pressure sensitivity of 3.3 kPa. With the broadband ultrasonic detection, our SPR-PAM has achieved high spatial resolution with relatively low anisotropy (i.e., 2.0 μm laterally and 8.4 μm axially). Three-dimensional high-resolution imaging of a single melanoma cell is demonstrated.

  6. An all-optical method of developing data communication system with error detection circuit

    NASA Astrophysics Data System (ADS)

    Mandal, Sumana; Mandal, Dhoumendra; Garai, Sisir Kumar

    2014-03-01

    The basic criterion of data communication is that received data should exactly be the replica of the transmitting data. If any error is introduced in the received data, then data transmission should be stopped immediately. In this article the authors have developed an all-optical method of data communication system with error detection mechanism that works with frequency encoded data. Basic building blocks of the proposed data communication scheme are parity generator and parity checker which are developed from all optical XOR logic gates. Simulation results testify the feasibility of the proposed scheme. These logic gates are developed exploiting nonlinear polarization rotation based frequency conversion and switching character of semiconductor optical amplifiers. The scheme with frequency encoded data, high speed of frequency conversion and polarization switching action of semiconductor optical amplifier offers secure, error free, faster data communication network.

  7. All-optically driven system in ultrasonic wave-based structural health monitoring

    NASA Astrophysics Data System (ADS)

    Bi, Siwen; Wu, Nan; Zhou, Jingcheng; Zhang, Haifeng; Wang, Xingwei

    2016-04-01

    Ultrasonic wave based structural health monitoring (SHM) is an innovative method for nondestructive detection and an area of growing interest. This is due to high demands for wireless detection in the field of structural engineering. Through optically exciting and detecting ultrasonic waves, electrical wire connections can be avoided, and non-contact SHM can be achieved. With the combination of piezoelectric transducer (PZT) (which possesses high heat resistance) and the noncontact detection, this system has a broad range of applications, even in extreme conditions. This paper reports an all-optically driven SHM system. The resonant frequencies of the PZT transducers are sensitive to a variety of structural damages. Experimental results have verified the feasibility of the all-optically driven SHM system.

  8. All-optical clock recovery based on simultaneous external injection-locking and self-seeding of a Fabry-Perot laser diode

    NASA Astrophysics Data System (ADS)

    Fang, Xiaohui; Wai, Ping Kong A.; Lu, Chao; Tam, Hwa Yaw; Qureshi, Khurram K.

    2011-02-01

    We proposed and demonstrated a novel, simple, and low cost method for all-optical clock recovery based on the switching between two injection-locked longitudinal modes in a dc-biased multi-quantum-well Fabry-Perot laser diode (FP-LD). The dc biased FP-LD is simultaneously injection-locked by a return-to-zero data signal at one of the longitudinal modes of the FP-LD and self-seeded at another longitudinal mode by using a uniform fiber Bragg grating as a feedback component. The powers and detunes of the data signal and self-seeding signal are chosen such that self-seeding is realized in the FP-LD only when data signal power is low. Clock signals of data streams at different data rates can be obtained by tuning the optical delay line in the external self-seeding loop. We have demonstrated all-optical clock recovery at 10 GHz. The pulse width, time-bandwidth product, side mode suppression ration, root mean square timing jitter, and average power of the recovered clock signals are 50 ps, 0.5, 50 dB, 248 fs, and 3.6 dBm, respectively. Clock recovery is possible at wavelength within the gain band of the FP-LD. We also find and explore in the experiment the influence of detune between the external data signal and the nearest FP-LD longitudinal mode to the recovered clock.

  9. Realization of All-Optical Multistate Switching in an Atomic Coherent Medium

    NASA Astrophysics Data System (ADS)

    Sheng, Jiteng; Khadka, Utsab; Xiao, Min

    2012-11-01

    We have experimentally observed optical multistability (OM) in an optical ring cavity containing three-level Λ-type Doppler-broadened rubidium atoms. The shape of the OM curve can be significantly modified by changing the power of the control laser field. An all-optical multistate switching or coding element is realized and flexibly controlled by adding a pulse sequence to the input (probe) intensity.

  10. Ultrafast all-optical temporal differentiators based on CMOS-compatible integrated-waveguide Bragg gratings.

    PubMed

    Rutkowska, K A; Duchesne, D; Strain, M J; Morandotti, R; Sorel, M; Azaña, J

    2011-09-26

    We report the first realization of integrated, all-optical first- and higher-order photonic differentiators operating at terahertz (THz) processing speeds. This is accomplished in a Silicon-on-Insulator (SOI) CMOS-compatible platform using a simple integrated geometry based on (π-)phase-shifted Bragg gratings. Moreover, we achieve on-chip generation of sub-picosecond Hermite-Gaussian pulse waveforms, which are noteworthy for applications in next-generation optical telecommunications.

  11. Temporal gap solitons and all-optical control of group delay in line-defect waveguides.

    PubMed

    Malaguti, S; Bellanca, G; Combrié, S; de Rossi, A; Trillo, S

    2012-10-19

    We show that a model based on anticrossing between highly group velocity-mismatched gap-guided and index-guided modes describes gap soliton propagation in photonic crystal waveguides. Such nonlinear solutions can be exploited for exploring new regimes such as all-optical control of group velocity (dispersionless slow light) over a submillimeter length scale, and propagation beyond the linear modal cutoff. The results are validated by means of finite-difference time domain simulations.

  12. 40-Gbit/s all-optical circulating shift register with an inverter.

    PubMed

    Hall, K L; Donnelly, J P; Groves, S H; Fennelly, C I; Bailey, R J; Napoleone, A

    1997-10-01

    We report what is believed to be the first demonstration of an all-optical circulating shift register using an ultrafast nonlinear interferometer with a polarization-insensitive semiconductor optical amplifier as the nonlinear switching element. The device operates at 40 Gbits/s, to our knowledge the highest speed demonstrated to date. Also, the demonstration proves the cascadability of the ultrafast nonlinear interferometric switch.

  13. Raman mediated all-optical cascadable inverter using silicon-on-insulator waveguides.

    PubMed

    Sen, Mrinal; Das, Mukul K

    2013-12-01

    In this Letter, we propose an all-optical circuit for a cascadable and integrable logic inverter based on stimulated Raman scattering. A maximum product criteria for noise margin is taken to analyze the cascadability of the inverter. Variation of noise margin for different model parameters is also studied. Finally, the time domain response of the inverter is analyzed for different widths of input pulses.

  14. All optical contention detection and resolution for asynchronous variable length optical packets switching

    NASA Astrophysics Data System (ADS)

    Farhat, Rim; Farhat, Amel; Menif, Mourad

    2016-04-01

    We proposed a novel 2×2 all optical packet switching router architecture supporting asynchronous, labelled and variablelength packet. A proof of concept through Matlab Simulink simulation is validated. Then we discussed the three possible scenarios to demonstrate the contention resolution technique based on deflection routing. We have showing that the contending packet is detected and forwarded according FIFO (First In First Out) strategy to another output.

  15. All-optical multibit address recognition at 20 Gb/s based on TOAD

    NASA Astrophysics Data System (ADS)

    Yan, Yumei; Wu, Jian; Lin, Jintong

    2005-04-01

    All-optical multibit address recognition at 20 Gb/s is demonstrated based on a special AND logic of terahertz optical asymmetric demultiplexer (TOAD). The semiconductor optical amplifier (SOA) used in the TOAD is biased at transparency status to accelerate the gain recovery. This is the highest bit rate that multibit address recognition is demonstrated with SOA-based interferometer. The experimental results show low pattern dependency. With this method, address recognition can be performed without separating address and payload beforehand.

  16. A phase insensitive all-optical router based on nonlinear lenslike planar waveguides.

    PubMed

    Mateo, Eduardo; Liñares, Jesús

    2005-05-02

    We present the design of an all-optical router based on the properties of both propagation and interaction of Gaussian beams in lenslike planar guides. Variational results of single co- and counterpropagation are derived and used to design three integrated optical devices, that is, a header extraction device, an optical bistable device and a data routing device, which perform an ultrafast, phase-insensitive and fiber compatible routing operation in the optical domain.

  17. New all-optical wavelength auto-router based on spatial solitons.

    PubMed

    Wu, Yaw-Dong

    2004-09-06

    We propose a novel all-optical wavelength auto-router based on spatial solitons. By using the swing effect of spatial solitons in a Kerr-type nonlinear medium, the proposed nonlinear waveguide structure could function as a self-routing wavelength division multiplexer (WDM). It could be a potential key component in the applications of ultra-high-speed and ultra-high-capacity optical communications and optical data processing systems.

  18. Realization of all-optical switch and diode via Raman gain process using a Kerr field

    NASA Astrophysics Data System (ADS)

    Abbas, Muqaddar; Qamar, Sajid; Qamar, Shahid

    2016-08-01

    The idea of optical photonic crystal, which is generated using two counter-propagating fields, is revisited to study gain-assisted all-optical switch and diode using Kerr field. Two counter-propagating fields with relative detuning Δ ν generate standing-wave field pattern which interacts with a four-level atomic system. The standing-wave field pattern acts like a static photonic crystal for Δ ν =0 , however, it behaves as a moving photonic crystal for Δ ν \

  19. Software Defined Networking (SDN) controlled all optical switching networks with multi-dimensional switching architecture

    NASA Astrophysics Data System (ADS)

    Zhao, Yongli; Ji, Yuefeng; Zhang, Jie; Li, Hui; Xiong, Qianjin; Qiu, Shaofeng

    2014-08-01

    Ultrahigh throughout capacity requirement is challenging the current optical switching nodes with the fast development of data center networks. Pbit/s level all optical switching networks need to be deployed soon, which will cause the high complexity of node architecture. How to control the future network and node equipment together will become a new problem. An enhanced Software Defined Networking (eSDN) control architecture is proposed in the paper, which consists of Provider NOX (P-NOX) and Node NOX (N-NOX). With the cooperation of P-NOX and N-NOX, the flexible control of the entire network can be achieved. All optical switching network testbed has been experimentally demonstrated with efficient control of enhanced Software Defined Networking (eSDN). Pbit/s level all optical switching nodes in the testbed are implemented based on multi-dimensional switching architecture, i.e. multi-level and multi-planar. Due to the space and cost limitation, each optical switching node is only equipped with four input line boxes and four output line boxes respectively. Experimental results are given to verify the performance of our proposed control and switching architecture.

  20. All-optical isolator under arbitrary linearly polarized fundamental wave in an optical superlattice.

    PubMed

    Yuan, Liang; Shi, Jianhong; Chen, Xianfeng

    2011-12-01

    We theoretically investigate an all-optical isolator under arbitrary linearly polarized fundamental wave (FW) input in an optical superlattice (OSL). The scheme is based on simultaneously phase matching the first-order Type I (oo-e) quasi-phase-matching (QPM) second-harmonic generation (SHG) process and higher-order Type 0 (ee-e) QPM SHG process in an OSL with a defect inserted in an asymmetrical position. Simulation results show that the contrast ratio of the all-optical isolator can maintain close to 1 under arbitrary linearly polarized FW. Thus, an all-optical isolator based on an OSL that is not sensitive to the direction of linear polarization can be realized. We also show that, with the defect in a strong asymmetry position, the length of the defect can be designed flexibly to maintain a high contrast ratio. Additionally, if the length of the OSL is longer, the nonreciprocal response can be realized for low optical intensities.

  1. All-optical single-sideband frequency upconversion utilizing the XPM effect in an SOA-MZI.

    PubMed

    Kim, Doo-Ho; Lee, Joo-Young; Choi, Hyung-June; Song, Jong-In

    2016-09-05

    An all-optical single sideband (OSSB) frequency upconverter based on the cross-phase modulation (XPM) effect is proposed and experimentally demonstrated to overcome the power fading problem caused by the chromatic dispersion of fiber in radio-over-fiber systems. The OSSB frequency upconverter consists of an arrayed waveguide grating (AWG) and a semiconductor optical amplifier Mach-Zehnder interferometer (SOA-MZI) and does not require an extra delay line used for phase noise compensation. The generated OSSB radio frequency (RF) signal transmitted over single-mode fibers up to 20 km shows a flat electrical RF power response as a function of the fiber length. The upconverted electrical RF signal at 48 GHz shows negligible degradation of the phase noise even without an extra delay line. The measured phase noise of the upconverted RF signal (48 GHz) is -74.72 dBc/Hz at an offset frequency of 10 kHz. The spurious free dynamic range (SFDR) measured by a two-tone test to estimate the linearity of the OSSB frequency upconverter is 72.5 dB·Hz2/3.

  2. Demonstration of 400 Gb/s optical PDM-OFDM superchannel unrepeatered transmission by all optical phase-conjugated copy

    NASA Astrophysics Data System (ADS)

    Chen, Yuanxiang; Li, Juhao; Zhu, Paikun; Wu, Zhongying; Chen, Jingbiao; He, Yongqi; Chen, Zhangyuan

    2016-12-01

    Unrepeatered transmission delivers data over a few hundred kilometers without in-line active elements and it can effectively reduce the line complexity and the overall system cost. In this paper, we propose all optical phase-conjugated copy (OPC) to improve optical signal noise ratio (OSNR) margin and nonlinear tolerance for unrepeatered transmission of polarization division multiplexing (PDM) optical superchannel with EDFA only amplification. Orthogonal pumps FWM scheme is utilized to generate the optical phase-conjugated copy. The original superchannel and the phase-conjugated copy are simultaneously transmitted and received. The phases of the copy symbols are conjugated and summed with the original superchannel symbols to suppress both linear noise and nonlinear phase noise at the receiver. The proposed OPC scheme is simple and effective in phase-conjugated copy generation and digital signal processing (DSP). What is more, it is transparent to signal bit rate and modulation format, which applies to optical superchannel transmission. We experimentally verify the proposed scheme on a 400 Gb/s optical polarization division multiplexing orthogonal frequency division multiplexing (PDM-OFDM) superchannel. A Q-factor improvement of 2.1 dB is achieved after 180 km SSMF unrepeatered transmission. The optimum launch power in OPC scheme increases from -3 dBm to -2 dBm. To verify the maximum reach, we extend fiber length and realize 240 km SSMF unrepeatered transmission.

  3. All-optical arithmetic unit with the help of terahertz-optical-asymmetric-demultiplexer-based tree architecture

    NASA Astrophysics Data System (ADS)

    Gayen, Dilip Kumar; Nath Roy, Jitendra

    2008-03-01

    An all-optical arithmetic unit with the help of terahertz-optical-asymmetric-demultiplexer (TOAD)-based tree architecture is proposed. We describe the all-optical arithmetic unit by using a set of all-optical multiplexer, all-optical full-adder, and optical switch. The all-optical arithmetic unit can be used to perform a fast central processor unit using optical hardware components. We have tried to exploit the advantages of both optical tree architecture and TOAD-based switch to design an integrated all-optical circuit that can perform binary addition, addition with carry, subtract with borrow, subtract (2's complement), double, increment, decrement, and transfer operations.

  4. Fixed weight Hopfield Neural Network based on optical implementation of all-optical MZI-XNOR logic gate

    NASA Astrophysics Data System (ADS)

    Nugamesh Mutter, Kussay; Mat Jafri, Mohd Zubir; Abdul Aziz, Azlan

    2010-05-01

    Many researches are conducted to improve Hopfield Neural Network (HNN) performance especially for speed and memory capacity in different approaches. However, there is still a significant scope of developing HNN using Optical Logic Gates. We propose here a new model of HNN based on all-optical XNOR logic gates for real time color image recognition. Firstly, we improved HNN toward optimum learning and converging operations. We considered each unipolar image as a set of small blocks of 3-pixels as vectors for HNN. This enables to save large number of images in the net with best reaching into global minima, and because there are only eight fixed states of weights so that only single iteration performed to construct a vector with stable state at minimum energy. HNN is useless in dealing with data not in bipolar representation. Therefore, HNN failed to work with color images. In RGB bands each represents different values of brightness, for d-bit RGB image it is simply consists of d-layers of unipolar. Each layer is as a single unipolar image for HNN. In addition, the weight matrices with stability of unity at the diagonal perform clear converging in comparison with no self-connecting architecture. Synchronously, each matrix-matrix multiplication operation would run optically in the second part, since we propose an array of all-optical XOR gates, which uses Mach-Zehnder Interferometer (MZI) for neurons setup and a controlling system to distribute timely signals with inverting to achieve XNOR function. The primary operation and simulation of the proposal HNN is demonstrated.

  5. All-optical logic circuits based on the polarization properties of non-degenerate four-wave mixing

    NASA Astrophysics Data System (ADS)

    Bhardwaj, Ashish Ishwar Singh

    2001-10-01

    This thesis investigates a new class of all-optical logic circuits that are based on the polarization properties of non-degenerate Four-Wave Mixing. Such circuits would be used in conjunction with a data modulation format where the information is coded on the states of polarization of the electric field. Schemes to perform multiple triple- product logic functions are discussed and it is shown that higher-level Boolean operations involving several bits can be implemented without resorting to the standard 2-input gates that are based on some form of switching. Instead, an entire hierarchy of more complex Boolean functions can be derived based on the selection rules of multi-photon scattering processes that can form a new classes of primitive building blocks for digital circuits. Possible applications of these circuits could involve some front-end signal processing to be performed all- optically in shared computer back-planes. As a simple illustration of this idea, a circuit performing error correction on a (3,1) Hamming Code is demonstrated. Error-free performance (Bit Error Rate of <10-9) at 2.5 Gbit/s is achieved after single-error correction on the Hamming word with 50 percent errors. The bit-rate is only limited by the bandwidth of available resources. Since Four-Wave Mixing is an ultrafast nonlinearity, these circuits offer the potential of computing at several terabits per second. Furthermore, it is shown that several Boolean functions can be performed in parallel in the same set of devices using different multi-photon scattering processes. The main objective of this thesis is to motivate a new paradigm of thought in digital circuit design. Challenges pertaining to the feasibility of these ideas are discussed.

  6. Performance analysis of an all-optical logic gate based on a single I/Q modulator with direct detection.

    PubMed

    Zhai, Yaxue; Tang, Xianfeng; Zhang, Xiaoguang; Xi, Lixia; Zhang, Wenbo

    2016-09-01

    This paper investigates the performance of an all-optical logic gate scheme based on a single in-phase and quadrature (I/Q) modulator with direct detection. The proposed scheme of an all-optical logic gate is simple, high speed, and easily reconfigured to realize 24 logic states by adjusting bias voltages, peak-to-peak voltages of the driven RF signals, and the phase shift. As the scheme to realize logic gates is based on the irregular use of a commercially available I/Q modulator and laser source, a specialized logic gate system including a laser, I/Q modulator, and driven RF module should be optimally designed to obtain the best performance. With the system's extinction ratio (ER) and Q-factor as metrics, the performance of the proposed logic gate scheme is analyzed theoretically and numerically in this paper. We first give a new theoretical model of the I/Q modulator. Next, taking the OR gate as an example, the simulations are carried out to analyze performance under the influence of some key factors in the system. Results show that the extinction ratio of the whole system is affected by the phase shift between the two arms of the I/Q modulator and the extinction ratios of two Mach-Zehnder modulators (MZMs), while Q-factor is further influenced by the output power of the laser and the insertion loss of the MZMs in the I/Q modulator. For an I/Q modulator with MZMs having an extinction ratio of 20 dB, the minimum laser output power to obtain a system's ER higher than 16 dB is 3 dBm, while in order to obtain a Q-factor higher than 6, the output power of the laser must not be <10  dBm.

  7. PPLN-based all-optical 40 Gbit/s ODB/AMI/FSK wavelength conversion and FSK logic NOT gate

    NASA Astrophysics Data System (ADS)

    Wang, J.; Sun, Q.; Sun, J.; Hu, Z.

    2009-07-01

    We propose and demonstrate all-optical wavelength conversion for optical duobinary (ODB), alternate-mark inversion (AMI), and frequency-shift keying (FSK) signals and a logic NOT gate for a FSK signal based on cascaded second-harmonic generation and difference-frequency generation (cSHG/DFG) in a periodically poled lithium niobate (PPLN) waveguide. ODB/AMI/FSK are generated from the demodulation of differential phase-shift keying (DPSK) using one-bit-delay fiber delay interferometer (FDI). PPLN-based 40 Gbit/s ODB/AMI/FSK wavelength conversion and FSK logic NOT gate are simultaneously implemented in the experiment.

  8. Wavelength-preserving polarization-insensitive all-optical 3R regenerator based on self- and cross-phase modulation and offset filtering utilizing Raman amplification

    NASA Astrophysics Data System (ADS)

    Chung, Sung Han

    Optical regeneration has the potential to significantly increase the reach of long-haul transmission systems. In this thesis, wavelength-preserving polarization-insensitive all-optical 3R regeneration is investigated and demonstrated for 10 and 40 Gb/s signals. The all-optical regenerator utilizes a self-pulsating laser for clock recovery, cross-phase modulation (XPM) based spectral broadening in a highly nonlinear fiber (HNLF) and offset filtering for retiming, and self-phase modulation based spectral broadening in a HNLF and offset filtering for reshaping. Raman amplification is used to increase the XPM-based spectral broadening and thus allow a design that meets the tradeoffs involved in simultaneously achieving good retiming and reshaping performance. The regenerator is shown to reduce amplitude noise and timing jitter while not causing a BER penalty. To fully validate the regeneration scheme, the cascadability is demonstrated using a recirculating loop. For a 10 Gb/s signal, with a regenerator spacing of 240 km, a return-to-zero, on-off-keyed (RZ-OOK) signal was transmitted over 18,000 km (75 loops) with a power penalty of 1.6 dB at a BER of 10 -9 compared to the back-to-back case. For a 40 Gb/s signal, with a regenerator spacing of 80 km, a RZ-OOK signal was transmitted over 8,000 km (100 loops) with a power penalty of 1.2 dB. In addition, all-optical 3R regeneration is demonstrated using a multimode quantum-dot Fabry Perot laser with ultra-low timing jitter.

  9. All-optical frequency downconversion technique utilizing a four-wave mixing effect in a single semiconductor optical amplifier for wavelength division multiplexing radio-over-fiber applications.

    PubMed

    Kim, Hyoung-Jun; Song, Jong-In

    2012-03-26

    An all-optical frequency downconversion utilizing a four-wave mixing effect in a single semiconductor optical amplifier (SOA) was experimentally demonstrated for wavelength division multiplexing (WDM) radio-over-fiber (RoF) applications. Two WDM optical radio frequency (RF) signals having 155 Mbps differential phase shift keying (DPSK) data at 28.5 GHz were simultaneously down-converted to two WDM optical intermediate frequency (IF) signals having an IF frequency of 4.5 GHz by mixing with an optical local oscillator (LO) signal having a LO frequency of 24 GHz in the SOA. The bit-error-rate (BER) performance of the RoF up-links with different optical fiber lengths employing all-optical frequency downconversion was investigated. The receiver sensitivity of the RoF up-link with a 6 km single mode fiber and an optical IF signal in an optical double-sideband format was approximately -8.5 dBm and the power penalty for simultaneous frequency downconversion was approximately 0.63 dB. The BER performance showed a strong dependence on the fiber length due to the fiber dispersion. The receiver sensitivity of the RoF up-link with the optical IF signal in the optical single-sideband format was reduced to approximately -17.4 dBm and showed negligible dependence on the fiber length.

  10. All-optical XNOR gate based on 2D photonic-crystal ring resonators

    NASA Astrophysics Data System (ADS)

    Moniem, Tamer A.

    2017-02-01

    A novel all-optical XNOR gate is proposed, which combines the nonlinear Kerr effect with photonic-crystal ring resonators (PCRRs). The total size of the proposed optical XNOR gate based on photonic crystals with a square lattice of silicon rods is equal to 35 × 21 μm. The proposed structure has a bandgap in the range from 0.32 to 0.44. To confirm the operation and feasibility of the overall system use is made of analytical and numerical simulation using the dimensional finite difference time domain (FDTD) and plane wave expansion (PWE) methods.

  11. An all-optical poling investigation of low absorbing azobenzene side-chain polymer films

    NASA Astrophysics Data System (ADS)

    Jia, Yajie; Wang, Gongming; Guo, Bin; Su, Wei; Zhang, Qijin

    2004-09-01

    All optical poling (AOP) processes of both the typical AOP material disperse red 1 (DR1) copolymer and a low absorbing side-chain poly(2-[4-(4-cyanophenylazo)phenoxy] hexyl methacrylate), called PCN6, were examined and compared. The trade-off between the optical seeding efficiency and the transparency of the nonlinear polymer was considered. Quasi-phase matched (QPM) second harmonic generation (SHG) in PCN6 films was demonstrated. A relaxation retardation effect of the photo-induced khgr(2) was also observed in thick PCN6 films.

  12. Applications of highly nonlinear chalcogenide glass fibers in ultrafast all-optical switches

    SciTech Connect

    Asobe, Masaki ); Kanamori, Terutoshi ); Kubodera, Ken'ichi )

    1993-08-01

    The authors report applications of chalcogenide glass fibers in ultrafast all-optical switches. The switching performance is studied with optical Kerr shutter experiments and through calculation analysis taking the effect of group velocity dispersion and two-photon absorption into account. The nonlinear refractive index of the As[sub 2]S[sub 3]-based glass is estimated to be n[sub 2] = 4.0 [times] 10[sup [minus]14](sm[sup 2]/W), which is higher by two orders of magnitude than silica glass fiber. They also discuss the capabilities of low power switching.

  13. All-optical photoacoustic imaging system using fiber ultrasound probe and hollow optical fiber bundle.

    PubMed

    Miida, Yusuke; Matsuura, Yuji

    2013-09-23

    An all-optical 3D photoacoustic imaging probe that consists of an optical fiber probe for ultrasound detection and a bundle of hollow optical fibers for excitation of photoacoustic waves was developed. The fiber probe for ultrasound is based on a single-mode optical fiber with a thin polymer film attached to the output end surface that works as a Fabry Perot etalon. The input end of the hollow fiber bundle is aligned so that each fiber in the bundle is sequentially excited. A thin and flexible probe can be obtained because the probe system does not have a scanning mechanism at the distal end.

  14. Fiber Lasers and all Optical Logic Gates for Header Processing in High-Bit Optical Networks

    NASA Astrophysics Data System (ADS)

    Barnett, Brandon Craig

    As information technologies push network capacities toward higher bit rates, fiber-optic communication networks will eventually be capable of transmitting data at a rate at which electronic switches cannot respond. A solution to this problem is to replace the electronics at the front and back ends of the transmission system where data enters and exists in optical format with all-optical header processors. In this thesis, I will describe how the header processor has been divided into all-optical switching modules, which will act as the basic building block for the header processing unit. Each module arises from the integration of an erbium -doped fiber laser and an all-optical logic gate. The erbium-doped fiber laser (EDFL) acts as a local power supply for the module. It restores the pulse shape, pulse amplitude, and timing of an incoming optical bit stream. The development of a short-pulse EDFL and a high-power EDFL for this application is described. The high-power EDFL employs a unique cavity design that eliminates multiple pulses when pumped with high powers. Data processing is performed within the module by all-optical logic gates, which switch due to the nonlinear interaction of one pulse of light with another in optical fiber. Therefore, these gates can work at the bit rate of the transmission system and avoid the bottlenecks inherent in electronic processors. The design and demonstration of a low-latency soliton-dragging gate and a low-birefringent nonlinear optical loop mirror (low-bi NOLM) logic gate are described. The two logic gates are optimized for energy contrast, switching energy, timing sensitivity, and cascadability. Logic functionality is also demonstrated. The thesis culminates in an experiment that integrates the laser and logic gate work by driving two cascaded low -bi NOLM's with an EDFL. It is shown that this experiment utilizes all the components necessary to read the header of a high-bit-rate data packet, bringing closure to the switching

  15. Dammann-grating-based passive phase locking by an all-optical feedback loop.

    PubMed

    Yang, Yifeng; Liu, Houkang; Zheng, Ye; Hu, Man; Liu, Chi; Qi, Yunfeng; He, Bing; Zhou, Jun; Wei, Yunrong; Lou, Qihong

    2014-02-01

    A Dammann grating is used as a spatial filter for a passive coherent beam combination (CBC) of three Yb-doped fiber amplifiers with an all-optical feedback loop. Using this diffractive-optics-based spatial filtering technique, we demonstrate CBC with 20 W output power, and the visibility of the far-field interference pattern is up to 88.7%. Measurements suggest that this approach is robust with respect to laboratory environment perturbations, and it can scale to high powers and large arrays.

  16. Low-power all-optical tunable plasmonic-mode coupling in nonlinear metamaterials

    SciTech Connect

    Zhang, Fan; Yang, Hong; Hu, Xiaoyong E-mail: qhgong@pku.edu.cn; Gong, Qihuang E-mail: qhgong@pku.edu.cn

    2014-03-31

    All-optical tunable plasmonic-mode coupling is realized in a nonlinear photonic metamaterial consisting of periodic arrays of gold asymmetrically split ring resonators, covered with a poly[(methyl methacrylate)-co-(disperse red 13 acrylate)] azobenzene polymer layer. The third-order optical nonlinearity of the azobenzene polymer is enormously enhanced by using resonant excitation. Under excitation with a 17-kW/cm{sup 2}, 532-nm pump light, plasmonic modes shift by 51 nm and the mode interval is enlarged by 30 nm. Compared with previous reports, the threshold pump intensity is reduced by five orders of magnitude, while extremely large tunability is maintained.

  17. All-optical switching in an open V-type atomic system

    NASA Astrophysics Data System (ADS)

    Jafarzadeh, H.

    2017-02-01

    In this paper, the optical bistability (OB) and absorption properties of a weak probe field in an open V-type three-level atomic system have been investigated. We found that the OB threshold could be reduced via spontaneously generated coherence (SGC), coherent and incoherent pump fields, atomic injection, and exit rates. We also found that the threshold intensity of OB in an open system was less than that in the closed system. The all-optical switching due to the OB has also been discussed.

  18. Analysis of all-optical temporal integrator employing phased-shifted DFB-SOA.

    PubMed

    Jia, Xin-Hong; Ji, Xiao-Ling; Xu, Cong; Wang, Zi-Nan; Zhang, Wei-Li

    2014-11-17

    All-optical temporal integrator using phase-shifted distributed-feedback semiconductor optical amplifier (DFB-SOA) is investigated. The influences of system parameters on its energy transmittance and integration error are explored in detail. The numerical analysis shows that, enhanced energy transmittance and integration time window can be simultaneously achieved by increased injected current in the vicinity of lasing threshold. We find that the range of input pulse-width with lower integration error is highly sensitive to the injected optical power, due to gain saturation and induced detuning deviation mechanism. The initial frequency detuning should also be carefully chosen to suppress the integration deviation with ideal waveform output.

  19. Design of polarization encoded all-optical 4-valued MAX logic gate and its applications

    NASA Astrophysics Data System (ADS)

    Chattopadhyay, Tanay; Nath Roy, Jitendra

    2013-07-01

    Quaternary maximum (QMAX) gate is one type of multi-valued logic gate. An all-optical scheme of polarization encoded quaternary (4-valued) MAX logic gate with the help of Terahertz Optical Asymmetric Demultiplexer (TOAD) based fiber interferometric switch is proposed and described. For the quaternary information processing in optics, the quaternary number (0, 1, 2, 3) can be represented by four discrete polarized states of light. Numerical simulation result confirming the described methods is given in this paper. Some applications of MAX gate in logical operation and memory device are also given.

  20. All-optical repetition rate multiplication of pseudorandom bit sequences by employing power coupler and equalizer

    NASA Astrophysics Data System (ADS)

    Sun, Zhenchao; Wang, Zhi; Wu, Chongqing; Wang, Fu; Li, Qiang

    2015-10-01

    A scheme for all-optical repetition rate multiplication of pseudorandom bit sequences (PRBS) is demonstrated with a precision delay feedback loop cascaded with a terahertz optical asymmetric demultiplexer (TOAD)-based power equalizer. Its feasibility has been verified by experiments, which show a multiplication for PRBS at cycle 2^7-1 from 2.5 to 10 Gb/s. This scheme can be employed for the rate multiplication of a much longer cycle PRBS at a much higher bit rate over 40 Gb/s if the time-delay, the loss, and the dispersion of an optical delay line are all precisely managed.

  1. All-optical packet header and payload separation for un-slotted optical packet switched networks

    NASA Astrophysics Data System (ADS)

    Ji, Wei; Zhang, Min; Ye, Peida

    2005-11-01

    A novel all-optical header and payload separation technique that can be utilized in un-slotted optical packet switched networks is presented. The technique uses a modified TOAD for packet header extraction with differential modulation scheme and two SOAs that perform a simple XOR operation between the packet and its self-derived header to get the separated payload. The main virtue of this system is simple structure and need not any additional continuous pulses. Through numerical simulations, the operating characteristics of the scheme are illustrated. In addition, the parameters of the system are discussed and designed to optimize the operation performance.

  2. Coherent-population-trapping resonances with linearly polarized light for all-optical miniature atomic clocks

    SciTech Connect

    Zibrov, Sergei A.; Velichansky, Vladimir L.; Novikova, Irina; Phillips, David F.; Walsworth, Ronald L.; Zibrov, Alexander S.; Taichenachev, Alexey V.; Yudin, Valery I.

    2010-01-15

    We present a joint theoretical and experimental characterization of the coherent population trapping (CPT) resonance excited on the D{sub 1} line of {sup 87}Rb atoms by bichromatic linearly polarized laser light. We observe high-contrast transmission resonances (up to approx =25%), which makes this excitation scheme promising for miniature all-optical atomic clock applications. We also demonstrate cancellation of the first-order light shift by proper choice of the frequencies and relative intensities of the two laser-field components. Our theoretical predictions are in good agreement with the experimental results.

  3. Three-photon-absorption resonance for all-optical atomic clocks

    SciTech Connect

    Zibrov, Sergei; Novikova, Irina; Phillips, David F.; Taichenachev, Aleksei V.; Yudin, Valeriy I.; Walsworth, Ronald L.; Zibrov, Alexander S.

    2005-07-15

    We report an experimental study of an all-optical three-photon-absorption resonance (known as an 'N resonance') and discuss its potential application as an alternative to atomic clocks based on coherent population trapping. We present measurements of the N-resonance contrast, width and light shift for the D{sub 1} line of {sup 87}Rb with varying buffer gases, and find good agreement with an analytical model of this resonance. The results suggest that N resonances are promising for atomic clock applications.

  4. All-optical subdiffraction multilevel data encoding onto azo-polymeric thin films.

    PubMed

    Savoini, Matteo; Biagioni, Paolo; Duò, Lamberto; Finazzi, Marco

    2009-03-15

    By exploiting photoinduced reorientation in azo-polymer thin films, we demonstrate all-optical polarization-encoded information storage with a scanning near-field optical microscope. In the writing routine, five-level bits are created by associating different bit values to different birefringence directions, induced in the polymer after illumination with linearly polarized light. The reading routine is then performed by implementing polarization-modulation techniques on the same near-field microscope in order to measure the encoded birefringence direction.

  5. Spectrally-efficient all-optical OFDM by WSS and AWG.

    PubMed

    Hoxha, J; Morosi, J; Shimizu, S; Martelli, P; Boffi, P; Wada, N; Cincotti, G

    2015-05-04

    We report on the transmission experiment of seven 12.5-GHz spaced all optical-orthogonal frequency division multiplexed (AO-OFDM) subcarriers over a 35-km fiber link, using differential quadrature phase shift keying (DQPSK) modulation and direct detection. The system does not require chromatic dispersion compensation, optical time gating at the receiver (RX) or cyclic prefix (CP), achieving the maximum spectral efficiency. We use a wavelength selective switch (WSS) at the transmitter (TX) to allow subcarrier assignment flexibility and optimal filter shaping; an arrayed waveguide grating (AWG) AO-OFDM demultiplexer is used at the RX, to reduce the system cost and complexity.

  6. All-optical radiation reaction at 10²¹ W/cm².

    PubMed

    Vranic, M; Martins, J L; Vieira, J; Fonseca, R A; Silva, L O

    2014-09-26

    Using full-scale 3D particle-in-cell simulations we show that the radiation reaction dominated regime can be reached in an all-optical configuration through the collision of a ~1 GeV laser wakefield accelerated electron bunch with a counterpropagating laser pulse. In this configuration the radiation reaction significantly reduces the energy of the particle bunch, thus providing clear experimental signatures for the process with currently available lasers. We also show that the transition between the classical and quantum radiation reaction could be investigated in the same configuration with laser intensities of 10²³ W/cm².

  7. All-optical tomography of electron spins in (In,Ga)As quantum dots

    NASA Astrophysics Data System (ADS)

    Varwig, S.; René, A.; Economou, Sophia E.; Greilich, A.; Yakovlev, D. R.; Reuter, D.; Wieck, A. D.; Reinecke, T. L.; Bayer, M.

    2014-02-01

    We demonstrate the basic features of an all-optical spin tomography on picosecond time scale. The magnetization vector associated with a mode-locked electron spin ensemble in singly charged quantum dots is traced by ellipticity measurements using picosecond laser pulses. After optical orientation the spins precess about a perpendicular magnetic field. By comparing the dynamics of two interacting ensembles with the dynamics of a single ensemble we find buildup of a spin component along the magnetic field in the two-ensemble case. This component arises from a Heisenberg-like spin-spin interaction.

  8. All-optical detection of magnetization precession in tunnel junctions under applied voltage

    NASA Astrophysics Data System (ADS)

    Sasaki, Yuta; Suzuki, Kazuya; Sugihara, Atsushi; Kamimaki, Akira; Iihama, Satoshi; Ando, Yasuo; Mizukami, Shigemi

    2017-02-01

    An all-optical time-resolved magneto-optical Kerr effect measurement of a micron-sized tunnel junction with a CoFeB electrode was performed. The femtosecond (fs) laser-induced magnetization precession was clearly observed at various magnetic field angles. The frequency f and relaxation time τ of the magnetization precession varied with the voltage applied via a MgO barrier. The precession dynamics were in accordance with Kittel’s ferromagnetic resonance mode, and the voltage-induced changes in f and τ were well explained by the voltage-induced change in the perpendicular magnetic anisotropy of -36 fJ/Vm.

  9. All-optical tailoring of single-photon spectra in a quantum-dot microcavity system

    NASA Astrophysics Data System (ADS)

    Breddermann, D.; Heinze, D.; Binder, R.; Zrenner, A.; Schumacher, S.

    2016-10-01

    Semiconductor quantum-dot cavity systems are promising sources for solid-state-based on-demand generation of single photons for quantum communication. Commonly, the spectral characteristics of the emitted single photon are fixed by system properties such as electronic transition energies and spectral properties of the cavity. In the present work we study cavity-enhanced single-photon generation from the quantum-dot biexciton through a partly stimulated nondegenerate two-photon emission. We show that frequency and linewidth of the single photon can be fully controlled by the stimulating laser pulse, ultimately allowing for efficient all-optical spectral shaping of the single photon.

  10. All-optical steering of laser-wakefield-accelerated electron beams.

    PubMed

    Popp, A; Vieira, J; Osterhoff, J; Major, Zs; Hörlein, R; Fuchs, M; Weingartner, R; Rowlands-Rees, T P; Marti, M; Fonseca, R A; Martins, S F; Silva, L O; Hooker, S M; Krausz, F; Grüner, F; Karsch, S

    2010-11-19

    We investigate the influence of a tilted laser-pulse-intensity front on laser-wakefield acceleration. Such asymmetric light pulses may be exploited to obtain control over the electron-bunch-pointing direction and in our case allowed for reproducible electron-beam steering in an all-optical way within an 8 mrad opening window with respect to the initial laser axis. We also discovered evidence of collective electron-betatron oscillations due to off-axis electron injection into the wakefield induced by a pulse-front tilt. These findings are supported by 3D particle-in-cell simulations.

  11. Ultrafast all-optical coherent control of single silicon vacancy colour centres in diamond

    PubMed Central

    Becker, Jonas Nils; Görlitz, Johannes; Arend, Carsten; Markham, Matthew; Becher, Christoph

    2016-01-01

    Complete control of the state of a quantum bit (qubit) is a fundamental requirement for any quantum information processing (QIP) system. In this context, all-optical control techniques offer the advantage of a well-localized and potentially ultrafast manipulation of individual qubits in multi-qubit systems. Recently, the negatively charged silicon vacancy centre (SiV−) in diamond has emerged as a novel promising system for QIP due to its superior spectral properties and advantageous electronic structure, offering an optically accessible Λ-type level system with large orbital splittings. Here, we report on all-optical resonant as well as Raman-based coherent control of a single SiV− using ultrafast pulses as short as 1 ps, significantly faster than the centre's phonon-limited ground state coherence time of about 40 ns. These measurements prove the accessibility of a complete set of single-qubit operations relying solely on optical fields and pave the way for high-speed QIP applications using SiV− centres. PMID:27841265

  12. Rate-distance tradeoff and resource costs for all-optical quantum repeaters

    NASA Astrophysics Data System (ADS)

    Pant, Mihir; Krovi, Hari; Englund, Dirk; Guha, Saikat

    2017-01-01

    We present a resource-performance tradeoff of an all-optical quantum repeater that uses photon sources, linear optics, photon detectors, and classical feedforward at each repeater node, but no quantum memories. We show that the quantum-secure key rate has the form R (η ) =D ηs bits per mode, where η is the end-to-end channel's transmissivity, and the constants D and s are functions of various device inefficiencies and the resource constraint, such as the number of available photon sources at each repeater node. Even with lossy devices, we show that it is possible to attain s <1 , and in turn outperform the maximum key rate attainable without quantum repeaters, Rdirect(η ) =-log2(1 -η ) ≈(1 /ln2 ) η bits per mode for η ≪1 , beyond a certain total range L , where η ˜e-α L in optical fiber. We also propose a suite of modifications to a recently proposed all-optical repeater protocol that ours builds upon, which lower the number of photon sources required to create photonic clusters at the repeaters so as to outperform Rdirect(η ) , from ˜1011 to ˜106 photon sources per repeater node. We show that the optimum separation between repeater nodes is independent of the total range L and is around 1.5 km for assumptions we make on various device losses.

  13. All-Optical Formation of Coherent Dark States of Silicon-Vacancy Spins in Diamond

    NASA Astrophysics Data System (ADS)

    Pingault, Benjamin; Becker, Jonas N.; Schulte, Carsten H. H.; Arend, Carsten; Hepp, Christian; Godde, Tillmann; Tartakovskii, Alexander I.; Markham, Matthew; Becher, Christoph; Atatüre, Mete

    2014-12-01

    Spin impurities in diamond can be versatile tools for a wide range of solid-state-based quantum technologies, but finding spin impurities that offer sufficient quality in both photonic and spin properties remains a challenge for this pursuit. The silicon-vacancy center has recently attracted much interest because of its spin-accessible optical transitions and the quality of its optical spectrum. Complementing these properties, spin coherence is essential for the suitability of this center as a spin-photon quantum interface. Here, we report all-optical generation of coherent superpositions of spin states in the ground state of a negatively charged silicon-vacancy center using coherent population trapping. Our measurements reveal a characteristic spin coherence time, T2* , exceeding 45 nanoseconds at 4 K. We further investigate the role of phonon-mediated coupling between orbital states as a source of irreversible decoherence. Our results indicate the feasibility of all-optical coherent control of silicon-vacancy spins using ultrafast laser pulses.

  14. Ultrasmall all-optical plasmonic switch and its application to superresolution imaging

    PubMed Central

    Wu, Hsueh-Yu; Huang, Yen-Ta; Shen, Po-Ting; Lee, Hsuan; Oketani, Ryosuke; Yonemaru, Yasuo; Yamanaka, Masahito; Shoji, Satoru; Lin, Kung-Hsuan; Chang, Chih-Wei; Kawata, Satoshi; Fujita, Katsumasa; Chu, Shi-Wei

    2016-01-01

    Because of their exceptional local-field enhancement and ultrasmall mode volume, plasmonic components can integrate photonics and electronics at nanoscale, and active control of plasmons is the key. However, all-optical modulation of plasmonic response with nanometer mode volume and unity modulation depth is still lacking. Here we show that scattering from a plasmonic nanoparticle, whose volume is smaller than 0.001 μm3, can be optically switched off with less than 100 μW power. Over 80% modulation depth is observed, and shows no degradation after repetitive switching. The spectral bandwidth approaches 100 nm. The underlying mechanism is suggested to be photothermal effects, and the effective single-particle nonlinearity reaches nearly 10−9 m2/W, which is to our knowledge the largest record of metallic materials to date. As a novel application, the non-bleaching and unlimitedly switchable scattering is used to enhance optical resolution to λ/5 (λ/9 after deconvolution), with 100-fold less intensity requirement compared to similar superresolution techniques. Our work not only opens up a new field of ultrasmall all-optical control based on scattering from a single nanoparticle, but also facilitates superresolution imaging for long-term observation. PMID:27063920

  15. Ultracompact all-optical logic gates based on nonlinear plasmonic nanocavities

    NASA Astrophysics Data System (ADS)

    Yang, Xiaoyu; Hu, Xiaoyong; Yang, Hong; Gong, Qihuang

    2017-01-01

    In this study, nanoscale integrated all-optical XNOR, XOR, and NAND logic gates were realized based on all-optical tunable on-chip plasmon-induced transparency in plasmonic circuits. A large nonlinear enhancement was achieved with an organic composite cover layer based on the resonant excitation-enhancing nonlinearity effect, slow light effect, and field confinement effect provided by the plasmonic nanocavity mode, which ensured a low excitation power of 200 μW that is three orders of magnitude lower than the values in previous reports. A feature size below 600 nm was achieved, which is a one order of magnitude lower compared to previous reports. The contrast ratio between the output logic states "1" and "0" reached 29 dB, which is among the highest values reported to date. Our results not only provide an on-chip platform for the study of nonlinear and quantum optics but also open up the possibility for the realization of nanophotonic processing chips based on nonlinear plasmonics.

  16. Angular and polarization dependence of all optical diode in one-dimensional photonic crystal

    NASA Astrophysics Data System (ADS)

    Jamshidi-Ghaleh, Kazem; Safari, Zeinab; Moslemi, Fatemeh

    2015-05-01

    The effect of the incident angle on all-optical diode (AOD) efficiency in a one-dimensional photonic crystal structure (1DPC) for TE and TM polarizations was studied. An asymmetric hybrid Fabry Perot resonator type 1DPC structure composed of linear and nonlinear materials was considered in this communication. The nonlinear transmission curves around the defect mode resonant frequency inside the photonic band gap for both TE and TM polarizations at different incident angles, from left to right (L-R) and right to left (R-L) incidences, are illustrated. Results showed that with increasing the incident angle, AOD performance efficiency increases only for TM polarization. The AOD efficiency increased to 80% for an incident angle of 60 degrees because of the dynamical shifting of the defect mode peak frequency caused by the intensity-dependency of the nonlinear layer refractive index along the z-axes. For TE polarization, the z-component of the electric field remained constant for all incident angles. The results of this study can be important in optical data communications and information analysis in all-optical integrated circuits.

  17. Ultrafast all-optical modulation with hyperbolic metamaterial integrated in Si photonic circuitry.

    PubMed

    Neira, Andres D; Wurtz, Gregory A; Ginzburg, Pavel; Zayats, Anatoly V

    2014-05-05

    The integration of optical metamaterials within silicon integrated photonic circuitry bears significantly potential in the design of low-power, nanoscale footprint, all-optical functionalities. We propose a novel concept and provide detailed analysis of an on-chip ultrafast all-optical modulator based on an hyperbolic metamaterial integrated in a silicon waveguide. The anisotropic metamaterial based on gold nanorods is placed on top of the silicon waveguide to form a modulator with a 300x440x600 nm(3) footprint. For the operating wavelength of 1.5 μm, the optimized geometry of the device has insertion loss of about 5 dB and a modulation depth of 35% with a sub-ps switching rate. The switching energy estimated from nonlinear transient dynamic numerical simulations is 3.7 pJ/bit when the transmission is controlled optically at a wavelength of 532 nm, resonant with the transverse plasmonic mode of the metamaterial. The switching mechanism is based on the control of the hybridization of eigenmodes in the metamaterial slab and the Si waveguide.

  18. Design for sequentially timed all-optical mapping photography with optimum temporal performance.

    PubMed

    Tamamitsu, Miu; Nakagawa, Keiichi; Horisaki, Ryoichi; Iwasaki, Atsushi; Oishi, Yu; Tsukamoto, Akira; Kannari, Fumihiko; Sakuma, Ichiro; Goda, Keisuke

    2015-02-15

    A recently developed ultrafast burst imaging method known as sequentially timed all-optical mapping photography (STAMP) [Nat. Photonics8, 695 (2014)10.1038/nphoton.2014.163] has been shown effective for studying a diverse range of complex ultrafast phenomena. Its all-optical image separation circumvents mechanical and electronic restrictions that traditional burst imaging methods have long struggled with, hence realizing ultrafast, continuous, burst-type image recording at a fame rate far beyond what is achievable with conventional methods. In this Letter, considering various design parameters and limiting factors, we present an optimum design for STAMP in terms of temporal properties including exposure time and frame rate. Specifically, we first derive master equations that can be used to predict the temporal performance of a STAMP system and then analyze them to realize optimum conditions. This Letter serves as a general guideline for the camera parameters of a STAMP system with optimum temporal performance that is expected to be of use for tackling problems in science that are previously unsolvable with conventional imagers.

  19. Engineered materials for all-optical helicity-dependent magnetic switching

    NASA Astrophysics Data System (ADS)

    Mangin, S.; Gottwald, M.; Lambert, C.-H.; Steil, D.; Uhlíř, V.; Pang, L.; Hehn, M.; Alebrand, S.; Cinchetti, M.; Malinowski, G.; Fainman, Y.; Aeschlimann, M.; Fullerton, E. E.

    2014-03-01

    The possibility of manipulating magnetic systems without applied magnetic fields have attracted growing attention over the past fifteen years. The low-power manipulation of the magnetization, preferably at ultrashort timescales, has become a fundamental challenge with implications for future magnetic information memory and storage technologies. Here we explore the optical manipulation of the magnetization in engineered magnetic materials. We demonstrate that all-optical helicity-dependent switching (AO-HDS) can be observed not only in selected rare earth-transition metal (RE-TM) alloy films but also in a much broader variety of materials, including RE-TM alloys, multilayers and heterostructures. We further show that RE-free Co-Ir-based synthetic ferrimagnetic heterostructures designed to mimic the magnetic properties of RE-TM alloys also exhibit AO-HDS. These results challenge present theories of AO-HDS and provide a pathway to engineering materials for future applications based on all-optical control of magnetic order.

  20. Electrical characterization of all-optical helicity-dependent switching in ferromagnetic Hall crosses

    NASA Astrophysics Data System (ADS)

    El Hadri, M. S.; Pirro, P.; Lambert, C.-H.; Bergeard, N.; Petit-Watelot, S.; Hehn, M.; Malinowski, G.; Montaigne, F.; Quessab, Y.; Medapalli, R.; Fullerton, E. E.; Mangin, S.

    2016-02-01

    We present an experimental study of all-optical helicity-dependent switching (AO-HDS) of ferromagnetic Pt/Co/Pt heterostructures with perpendicular magnetic anisotropy. The sample is patterned into a Hall cross and the AO-HDS is measured via the anomalous Hall effect. This all-electrical probing of the magnetization during AO-HDS enables a statistical quantification of the switching ratio for different laser parameters, such as the threshold power to achieve AO-HDS and the exposure time needed to reach complete switching at a given laser power. We find that the AO-HDS is a cumulative process, a certain number of optical pulses is needed to obtain a full and reproducible helicity-dependent switching. The deterministic switching of the ferromagnetic Pt/Co/Pt Hall cross provides a full "opto-spintronic device," where the remanent magnetization can be all-optically and reproducibly written and erased without the need of an external magnetic field.

  1. All-optical binary logic unit (BLU) using frequency encoded data

    NASA Astrophysics Data System (ADS)

    Mandal, Dhoumendra; Garai, Sisir Kumar

    2015-03-01

    In frequency division multiplexing based communication network frequency encoded data is very important. In this communication, authors propose a new approach of developing an all-optical binary logic unit (BLU) by means of which sixteen different types of binary logic operations can be performed using frequency encoded data. The authors first develop all-optical NOT, AND, OR, XOR, etc. logic gates exploiting the polarization switching character of semiconductor optical amplifier which works based on the principle of nonlinear state of polarization rotation of the probe beam. Finally these logic gates are coupled by means of polarization switches, and activated to implement different logic operations as desired using control beams of different frequencies, after being proper routing the control beams by means of 16:1 MUX and 1:16 DMUX. Frequency conversion by polarization switching character of SOA is very efficient and faster with least optical power consumption, and therefore our proposed scheme of binary logic unit with frequency encoded data offers bit error free secure different binary logic operations with faster speed of processing. Simulation result reflects the feasibility of the proposed scheme.

  2. Optical subcarrier generation and multiplexing scheme for all-optical networks

    NASA Astrophysics Data System (ADS)

    Sanchez, Sonia; Donkor, Eric

    2001-07-01

    There is demand for high-sped all-optical networks for the next generation internet that can transport the data header and packet of information at rates of between 40-100 Gb/s. Such networks will require high bandwidth and high-speed data transport. DWFM has been proposed as a viable scheme to implement such networks. Recently we reported the generation of optical subcarrier frequencies having bandwidth of the order of 2.5-3 terahertz. We prose a scheme for the design of high-density optical networks, in which the header is carried over the subcarrier frequencies and the packets are carried over the optical wavelengths. This scheme has many advantages, for example, it can allow for separate processing of header and packet, as well as provide higher bandwidth and high-speed data transport. We shall discuss the generation scheme for the terahertz optical subcarriers, a modulation scheme for these carriers, and how they are multiplexed in an all-optical network architecture.

  3. All-optical phase modulated format conversion for high transmission rates based on fiber nonlinearity

    NASA Astrophysics Data System (ADS)

    Duarte, Vanessa C.; Drummond, Miguel V.; Nogueira, Rogério N.

    2013-11-01

    Advanced modulation formats are an emerging area since they allow reducing the symbol rate while encoding more bits per symbol. This allows higher spectral efficiencies. In addition, we can achieve higher data rates using lower-speed equipment like in all-optical format conversion systems, an important step for the development of systems with high transmission rates. In this paper we study the impact of some impairments found in all-optical advanced format conversions based on cross phase modulation (XPM) on a highly nonlinear fiber (HNLF), such as amplified spontaneous emission (ASE), nonlinear fiber length and group velocity dispersion (GVD), and analyze its performance based on error vector magnitude (EVM) for different bitrate transmissions. This simulation study is applied on earlier proposed phase modulated format conversion where n nonreturn-to-zero on-off keying (NRZ-OOK) channels at 10 Gb/s are converted into a return-to-zero m phase shift keying (RZ-mPSK) at 20Gb/s. We extend the work with simulations and show the results for n NRZ-OOK channels at 20Gb/s, 40 Gb/s and 50Gb/s to RZ-PSK at 40Gb/s, 80 Gb/s and 100Gb/s, respectively.

  4. Two-color, 30 second microwave-accelerated Metal-Enhanced Fluorescence DNA assays: a new Rapid Catch and Signal (RCS) technology.

    PubMed

    Dragan, Anatoliy I; Golberg, Karina; Elbaz, Amit; Marks, Robert; Zhang, Yongxia; Geddes, Chris D

    2011-03-07

    For analyses of DNA fragment sequences in solution we introduce a 2-color DNA assay, utilizing a combination of the Metal-Enhanced Fluorescence (MEF) effect and microwave-accelerated DNA hybridization. The assay is based on a new "Catch and Signal" technology, i.e. the simultaneous specific recognition of two target DNA sequences in one well by complementary anchor-ssDNAs, attached to silver island films (SiFs). It is shown that fluorescent labels (Alexa 488 and Alexa 594), covalently attached to ssDNA fragments, play the role of biosensor recognition probes, demonstrating strong response upon DNA hybridization, locating fluorophores in close proximity to silver NPs, which is ideal for MEF. Subsequently the emission dramatically increases, while the excited state lifetime decreases. It is also shown that 30s microwave irradiation of wells, containing DNA molecules, considerably (~1000-fold) speeds up the highly selective hybridization of DNA fragments at ambient temperature. The 2-color "Catch and Signal" DNA assay platform can radically expedite quantitative analysis of genome DNA sequences, creating a simple and fast bio-medical platform for nucleic acid analysis.

  5. Silicon Photonics for All-Optical Processing and High-Bandwidth-Density Interconnects

    NASA Astrophysics Data System (ADS)

    Ophir, Noam

    The first chapter of the thesis provides motivation for the integration of silicon photonic modules into compute systems and surveys some of the recent developments in the field. The second chapter then proceeds to detail a technical case study of silicon photonic microring-based WDM links' scalability and power efficiency for these chip I/O applications which could be developed in the intermediate future. The analysis, initiated originally for a workshop on optical and electrical board and rack level interconnects, looks into a detailed model of the optical power budget for such a link capturing both single-channel aspects as well as WDM-operation-related considerations which are unique for a microring physical characteristics. The third chapter, while continuing on the theme silicon photonic high bandwidth density links, proceeds to detail the first experimental demonstration and characterization of an on-chip spatial division multiplexing (SDM) scheme based on microrings for the multiplexing and demultiplexing functionalities. In the context of more forward looking optical network-on-chip environments, SDM-enabled WDM photonic interconnects can potentially achieve superior bandwidth densities per waveguide compared to WDM-only photonic interconnects. The microring-based implementation allows dynamic tuning of the multiplexing and demultiplexing characteristic of the system which allows operation on WDM grid as well device tuning to combat intra-channel crosstalk. The characterization focuses on the first reported power penalty measurements for on-chip silicon photonic SDM link showing minimal penalties achievable with 3 spatial modes concurrently operating on a single waveguide with 10-Gb/s data carried by each mode. The fourth, fifth, and sixth chapters shift in topic from the application of silicon photonics to communication links to the evolving use of silicon waveguides for nonlinear all-optical processing. Chapter four primarily introduces and motivates

  6. Large-scale photonic integration for advanced all-optical routing functions

    NASA Astrophysics Data System (ADS)

    Nicholes, Steven C.

    Advanced InP-based photonic integrated circuits are a critical technology to manage the increasing bandwidth demands of next-generation all-optical networks. Integrating many of the discrete functions required in optical networks into a single device provides a reduction in system footprint and optical losses by eliminating the fiber coupling junctions between components. This translates directly into increased system reliability and cost savings. Although many key network components have been realized via InP-based monolithic integration over the years, truly large-scale photonic ICs have only recently emerged in the marketplace. This lag-time has been mostly due to historically low device yields. In all-optical routing applications, large-scale photonic ICs may be able to address two of the key roadblocks associated with scaling modern electronic routers to higher capacities---namely, power and size. If the functions of dynamic wavelength conversion and routing are moved to the optical layer, we can eliminate the need for power-hungry optical-to-electrical (O/E) and electrical-to-optical (E/O) data conversions at each router node. Additionally, large-scale photonic ICs could reduce the footprint of such a system by combining the similar functions of each port onto a single chip. However, robust design and manufacturing techniques that will enable high-yield production of these chips must be developed. In this work, we demonstrate a monolithic tunable optical router (MOTOR) chip consisting of an array of eight 40-Gbps wavelength converters and a passive arrayed-waveguide grating router that functions as the packet-forwarding switch fabric of an all-optical router. The device represents one of the most complex InP photonic ICs ever reported, with more than 200 integrated functional elements in a single chip. Single-channel 40 Gbps wavelength conversion and channel switching using 231-1 PRBS data showed a power penalty as low as 4.5 dB with less than 2 W drive power

  7. Microwave Ovens

    MedlinePlus

    ... Emitting Products Radiation-Emitting Products and Procedures Home, Business, and Entertainment Products Microwave ... for Consumers Laws, Regulations & Standards Industry Guidance Other Resources Description Microwave ...

  8. Self-homodyne 24×32-QAM superchannel receiver enabled by all-optical comb regeneration using brillouin amplification.

    PubMed

    Lorences-Riesgo, Abel; Mazur, Mikael; Eriksson, Tobias A; Andrekson, Peter A; Karlsson, Magnus

    2016-12-26

    We demonstrate and characterize an all-optical self-homodyne (SH) frequency superchannel enabled by comb regeneration at the receiver. In order to generate the superchannel, we use a frequency comb with 26 carriers spaced by 25 GHz at the transmitter, from which 24 carriers are modulated with polarization-multiplexed 32 quadrature amplitude modulation (PM 32-QAM) data. To enable comb regeneration at the receiver side, the two central carriers remain unmodulated. High fidelity comb regeneration is achieved by filtering the two unmodulated carriers with an approximately 25 MHz wide optical filter based on Brillouin amplification before a parametric mixer. The carriers from the regenerated comb are then used as local oscillator for SH detection. We demonstrate that all 24 carriers can be detected with an optical signal-to-noise ratio (OSNR) penalty lower than 2.5 dB in a back-to-back scenario. We also demonstrate that the whole superchannel can be transmitted through 120 km of single-mode fiber (SMF) and be detected with bit-error rate (BER) below 0.015.

  9. Terahertz all-optical NOR and AND logic gates based on 2D photonic crystals

    NASA Astrophysics Data System (ADS)

    Parandin, Fariborz; Karkhanehchi, Mohammad Mehdi

    2017-01-01

    Usually, photonic crystals are used in designing optical logic gates. This study focuses on the design and simulation of an all optical NOR and AND logic gates based on two dimensional photonic crystals. The simplicity of the proposed structure is a characteristic feature of this designation. Finite Difference Time Domain (FDTD) as well as Plane Wave Expansion (PWE) methods have been used for this structural analysis. The simulation results revealed an increase in the interval between "zero" and "one" logic levels. Also, the simple structure and its small size demonstrate the usefulness of this structure in optical integrated circuits. The proposed optical gates can operate with a bit rate of about 1.54 Tbit/s.

  10. All-optical switch using optically controlled two mode interference coupler.

    PubMed

    Sahu, Partha Pratim

    2012-05-10

    In this paper, we have introduced optically controlled two-mode interference (OTMI) coupler having silicon core and GaAsInP cladding as an all-optical switch. By taking advantage of refractive index modulation by launching optical pulse into cladding region of TMI waveguide, we have shown optically controlled switching operation. We have studied optical pulse-controlled coupling characteristics of the proposed device by using a simple mathematical model on the basis of sinusoidal modes. The device length is less than that of previous work. It is also seen that the cross talk of the OTMI switch is not significantly increased with fabrication tolerances (±δw) in comparison with previous work.

  11. All-Optical Switching of Magnetic Tunnel Junctions with Single Subpicosecond Laser Pulses

    NASA Astrophysics Data System (ADS)

    Chen, Jun-Yang; He, Li; Wang, Jian-Ping; Li, Mo

    2017-02-01

    The magnetic tunnel junction (MTJ) is one of the most important building blocks of spintronic logic and memory components for beyond-CMOS computation and communication. Although switching of MTJs without magnetic field has been achieved by charge and spin current injection, the operation speed is limited fundamentally by the spin-precession time to many picoseconds. We report the demonstration of ultrafast all-optical switching of an MTJ using single subpicosecond infrared laser pulses. This optically switchable MTJ uses ferrimagnetic Gd(Fe,Co) as the free layer and its switching is read out by measuring its tunneling magnetoresistance with a Δ R /R ratio of 0.6%. A switching repetition rate at MHz has been demonstrated, but the fundamental upper limit should be higher than tens of GHz rate. This result represents an important step toward integrated optospintronic devices that combines spintronics and photonics technologies to enable ultrafast conversion between fundamental information carriers of electron spins and photons.

  12. Nanoscale sub-100 picosecond all-optical magnetization switching in GdFeCo microstructures.

    PubMed

    Le Guyader, L; Savoini, M; El Moussaoui, S; Buzzi, M; Tsukamoto, A; Itoh, A; Kirilyuk, A; Rasing, T; Kimel, A V; Nolting, F

    2015-01-12

    Ultrafast magnetization reversal driven by femtosecond laser pulses has been shown to be a promising way to write information. Seeking to improve the recording density has raised intriguing fundamental questions about the feasibility of combining ultrafast temporal resolution with sub-wavelength spatial resolution for magnetic recording. Here we report on the experimental demonstration of nanoscale sub-100 ps all-optical magnetization switching, providing a path to sub-wavelength magnetic recording. Using computational methods, we reveal the feasibility of nanoscale magnetic switching even for an unfocused laser pulse. This effect is achieved by structuring the sample such that the laser pulse, via both refraction and interference, focuses onto a localized region of the structure, the position of which can be controlled by the structural design. Time-resolved photo-emission electron microscopy studies reveal that nanoscale magnetic switching employing such focusing can be pushed to the sub-100 ps regime.

  13. All-optical switching in a continuously operated and strongly coupled atom-cavity system

    NASA Astrophysics Data System (ADS)

    Dutta, Sourav; Rangwala, S. A.

    2017-03-01

    We experimentally demonstrate collective strong coupling, optical bi-stability (OB), and all-optical switching in a system consisting of ultracold 85Rb atoms, trapped in a dark magneto-optical trap (DMOT), and coupled to an optical Fabry-Perot cavity. The strong coupling is established by measuring the vacuum Rabi splitting (VRS) of a weak on-axis probe beam. The dependence of VRS on the probe beam power is measured, and bi-stability in the cavity transmission is observed. We demonstrate control over the transmission of the probe beam through the atom-cavity system using a free-space off-axis control beam and show that the cavity transmission can be switched on and off in micro-second timescales using micro-Watt control powers. The utility of the system as a tool for sensitive, in-situ and rapid measurements is envisaged.

  14. High-speed all-optical logic inverter based on stimulated Raman scattering in silicon nanocrystal.

    PubMed

    Sen, Mrinal; Das, Mukul K

    2015-11-01

    In this paper, we propose a new device architecture for an all-optical logic inverter (NOT gate), which is cascadable with a similar device. The inverter is based on stimulated Raman scattering in silicon nanocrystal waveguides, which are embedded in a silicon photonic crystal structure. The Raman response function of silicon nanocrystal is evaluated to explore the transfer characteristic of the inverter. A maximum product criterion for the noise margin is taken to analyze the cascadability of the inverter. The time domain response of the inverter, which explores successful inversion operation at 100 Gb/s, is analyzed. Propagation delay of the inverter is on the order of 5 ps, which is less than the delay in most of the electronic logic families as of today. Overall dimension of the device is around 755  μm ×15  μm, which ensures integration compatibility with the matured silicon industry.

  15. All-optical image processing and compression based on Haar wavelet transform.

    PubMed

    Parca, Giorgia; Teixeira, Pedro; Teixeira, Antonio

    2013-04-20

    Fast data processing and compression methods based on wavelet transform are fundamental tools in the area of real-time 2D data/image analysis, enabling high definition applications and redundant data reduction. The need for information processing at high data rates motivates the efforts on exploiting the speed and the parallelism of the light for data analysis and compression. Among several schemes for optical wavelet transform implementation, the Haar transform offers simple design and fast computation, plus it can be easily implemented by optical planar interferometry. We present an all optical scheme based on an asymmetric couplers network for achieving fast image processing and compression in the optical domain. The implementation of Haar wavelet transform through a 3D passive structure is supported by theoretical formulation and simulations results. Asymmetrical coupler 3D network design and optimization are reported and Haar wavelet transform, including compression, was achieved, thus demonstrating the feasibility of our approach.

  16. All-optical phase modulation in a cavity-polariton Mach–Zehnder interferometer

    PubMed Central

    Sturm, C.; Tanese, D.; Nguyen, H.S.; Flayac, H.; Galopin, E.; Lemaître, A.; Sagnes, I.; Solnyshkov, D.; Amo, A.; Malpuech, G.; Bloch, J.

    2014-01-01

    Quantum fluids based on light is a highly developing research field, since they provide a nonlinear platform for developing optical functionalities and quantum simulators. An important issue in this context is the ability to coherently control the properties of the fluid. Here we propose an all-optical approach for controlling the phase of a flow of cavity-polaritons, making use of their strong interactions with localized excitons. Here we illustrate the potential of this method by implementing a compact exciton–polariton interferometer, which output intensity and polarization can be optically controlled. This interferometer is cascadable with already reported polariton devices and is promising for future polaritonic quantum optic experiments. Complex phase patterns could be also engineered using this optical method, providing a key tool to build photonic artificial gauge fields. PMID:24513781

  17. Artificial eye for scotopic vision with bioinspired all-optical photosensitivity enhancer

    NASA Astrophysics Data System (ADS)

    Liu, Hewei; Huang, Yinggang; Jiang, Hongrui

    2016-04-01

    The ability to acquire images under low-light conditions is critical for many applications. However, to date, strategies toward improving low-light imaging primarily focus on developing electronic image sensors. Inspired by natural scotopic visual systems, we adopt an all-optical method to significantly improve the overall photosensitivity of imaging systems. Such optical approach is independent of, and can effectively circumvent the physical and material limitations of, the electronics imagers used. We demonstrate an artificial eye inspired by superposition compound eyes and the retinal structure of elephantnose fish. The bioinspired photosensitivity enhancer (BPE) that we have developed enhances the image intensity without consuming power, which is achieved by three-dimensional, omnidirectionally aligned microphotocollectors with parabolic reflective sidewalls. Our work opens up a previously unidentified direction toward achieving high photosensitivity in imaging systems.

  18. Artificial eye for scotopic vision with bioinspired all-optical photosensitivity enhancer.

    PubMed

    Liu, Hewei; Huang, Yinggang; Jiang, Hongrui

    2016-04-12

    The ability to acquire images under low-light conditions is critical for many applications. However, to date, strategies toward improving low-light imaging primarily focus on developing electronic image sensors. Inspired by natural scotopic visual systems, we adopt an all-optical method to significantly improve the overall photosensitivity of imaging systems. Such optical approach is independent of, and can effectively circumvent the physical and material limitations of, the electronics imagers used. We demonstrate an artificial eye inspired by superposition compound eyes and the retinal structure of elephantnose fish. The bioinspired photosensitivity enhancer (BPE) that we have developed enhances the image intensity without consuming power, which is achieved by three-dimensional, omnidirectionally aligned microphotocollectors with parabolic reflective sidewalls. Our work opens up a previously unidentified direction toward achieving high photosensitivity in imaging systems.

  19. Tuning all-Optical Analog to Electromagnetically Induced Transparency in nanobeam cavities using nanoelectromechanical system

    PubMed Central

    Shi, Peng; Zhou, Guangya; deng, Jie; Tian, Feng; Chau, Fook Siong

    2015-01-01

    We report the observations of all-optical electromagnetically induced transparency in nanostructures using waveguide side-coupled with photonic crystal nanobeam cavities, which has measured linewidths much narrower than individual resonances. The quality factor of transparency resonance can be 30 times larger than those of measured individual resonances. When the gap between cavity and waveguide is reduced to 10 nm, the bandwidth of destructive interference region can reach 10 nm while the width of transparency resonance is 0.3 nm. Subsequently, a comb-drive actuator is introduced to tune the line shape of the transparency resonance. The width of the peak is reduced to 15 pm and the resulting quality factor exceeds 105. PMID:26415907

  20. Multiport InP monolithically integrated all-optical wavelength router.

    PubMed

    Zheng, Xiu; Raz, Oded; Calabretta, Nicola; Zhao, Dan; Lu, Rongguo; Liu, Yong

    2016-08-15

    An indium phosphide-based monolithically integrated wavelength router is demonstrated in this Letter. The wavelength router has four input ports and four output ports, which integrate four wavelength converters and a 4×4 arrayed-waveguide grating router. Each wavelength converter is achieved based on cross-gain modulation and cross-phase modulation effects in a semiconductor optical amplifier. Error-free wavelength switching for a non-return-to-zero 231-1 ps eudorandom binary sequence at 40 Gb/s data rate is performed. Both 1×4 and 3×1 all-optical routing functions of this chip are demonstrated for the first time with power penalties as low as 3.2 dB.

  1. Integrated holographic system for all-optical manipulation of developing embryos

    PubMed Central

    Torres-Mapa, Maria Leilani; Antkowiak, Maciej; Cizmarova, Hana; Ferrier, David E. K.; Dholakia, Kishan; Gunn-Moore, Frank J.

    2011-01-01

    We demonstrate a system for the combined optical injection and trapping of developing embryos. A Ti:sapphire femtosecond laser in tandem with a spatial light modulator, is used to perform fast and accurate beam-steering and multiplexing. We show successful intracellular delivery of a range of impermeable molecules into individual blastomeres of the annelid Pomatoceros lamarckii embryo by optoinjection, even when the embryo is still enclosed in a chorion. We also demonstrate the ability of the femtosecond laser optoinjection to deliver materials into inner layers of cells in a well-developed embryo. By switching to the continuous wave mode of the Ti:sapphire laser, the same system can be employed to optically trap and orient the 60 μm sized P. lamarckii embryo whilst maintaining its viability. Hence, a complete all-optical manipulation platform is demonstrated paving the way towards single-cell genetic modification and cell lineage mapping in emerging developmental biology model species. PMID:21698019

  2. All-optical microfluidic circuit for biochemical and cellular analysis powered by photoactive nanoparticles

    NASA Astrophysics Data System (ADS)

    Liu, Gang L.; Kim, Jaeyoun; Lee, Luke P.

    2006-08-01

    We have invented a novel all-optical-logic microfluidic system which is automatically controlled only by visible or near infrared light with down to submilliwatt power. No electric power supply, no external or MEMS pump, no tubings or connectors, no microfluidic valves, nor surface patterning are required in our system. Our device only consists of a single-layer PDMS microfluidic chip and newly invented photoactive nanoparticles. Our photoactive nanoparticles are capable of converting optical energy to hydrodynamic energy in fluids. The nanoparticle themselves are biocompatible and can be biofunctionalized. Via these photoactive nanoparticles, we used only light to drive, guide, switch and mix liquid in optofluidic logic circuits with desired speeds and directions. We demonstrated the optofluidic controls in transportation of biomolecules and cells.

  3. Femtosecond all-optical synchronization of an X-ray free-electron laser

    DOE PAGES

    Schulz, S.; Grguraš, I.; Behrens, C.; ...

    2015-01-20

    Many advanced applications of X-ray free-electron lasers require pulse durations and time resolutions of only a few femtoseconds. To generate these pulses and to apply them in time-resolved experiments, synchronization techniques that can simultaneously lock all independent components, including all accelerator modules and all external optical lasers, to better than the delivered free-electron laser pulse duration, are needed. Here we achieve all-optical synchronization at the soft X-ray free-electron laser FLASH and demonstrate facility-wide timing to better than 30 fs r.m.s. for 90 fs X-ray photon pulses. Crucially, our analysis indicates that the performance of this optical synchronization is limited primarilymore » by the free-electron laser pulse duration, and should naturally scale to the sub-10 femtosecond level with shorter X-ray pulses.« less

  4. All-optical Mach-Zehnder modulator using a photochromic dye-doped polymer

    NASA Astrophysics Data System (ADS)

    Kang, Jae-Wook; Kim, Jang-Joo; Kim, Eunkyoung

    2002-03-01

    An all-optical Mach-Zehnder modulator is demonstrated which is composed of a polymer waveguide doped with a photochromic dye in the core and a thick light blocking metal layer on it. The metal layer was opened on one arm of the Mach-Zehnder modulator, so that only one arm of the modulator could be irradiated by modulation light, thus allowing a differential phase shift. The optical modulator exhibited an extinction ratio of about -12 dB at a wavelength of 1.55 μm. A simple kinetic model developed to delineate the refractive index change in the dye-doped polymer film was applied to predict the evolution of the modulation characteristics.

  5. A novel noninvasive all optical technique to monitor physiology of an exercising muscle

    NASA Astrophysics Data System (ADS)

    Saxena, Vishal; Marcu, Laura; Karunasiri, Gamani

    2008-11-01

    An all optical technique based on near-infrared spectroscopy and mid-infrared imaging (MIRI) is applied as a noninvasive, in vivo tool to monitor the vascular status of skeletal muscle and the physiological changes that occur during exercise. A near-infrared spectroscopy (NIRS) technique, namely, steady state diffuse optical spectroscopy (SSDOS) along with MIRI is applied for monitoring the changes in the values of tissue oxygenation and thermometry of an exercising muscle. The NIRS measurements are performed at five discrete wavelengths in a spectral window of 650-850 nm and MIRI is performed in a spectral window of 8-12 µm. The understanding of tissue oxygenation status and the behavior of the physiological parameters derived from thermometry may provide a useful insight into muscle physiology, therapeutic response and treatment.

  6. Artificial eye for scotopic vision with bioinspired all-optical photosensitivity enhancer

    PubMed Central

    Liu, Hewei; Huang, Yinggang; Jiang, Hongrui

    2016-01-01

    The ability to acquire images under low-light conditions is critical for many applications. However, to date, strategies toward improving low-light imaging primarily focus on developing electronic image sensors. Inspired by natural scotopic visual systems, we adopt an all-optical method to significantly improve the overall photosensitivity of imaging systems. Such optical approach is independent of, and can effectively circumvent the physical and material limitations of, the electronics imagers used. We demonstrate an artificial eye inspired by superposition compound eyes and the retinal structure of elephantnose fish. The bioinspired photosensitivity enhancer (BPE) that we have developed enhances the image intensity without consuming power, which is achieved by three-dimensional, omnidirectionally aligned microphotocollectors with parabolic reflective sidewalls. Our work opens up a previously unidentified direction toward achieving high photosensitivity in imaging systems. PMID:26976565

  7. Nonlinear interference effects and all-optical switching in optically dense inhomogeneously broadened media

    SciTech Connect

    Popov, A.K.; Myslivets, S.A.; George, Thomas F.

    2005-04-01

    Specific features of nonlinear interference processes at quantum transitions in near- and fully resonant Doppler-broadened optically dense media are studied. The possibility of all-optical switching of the medium to opaque or, alternatively, to absolutely transparent, or even to strongly amplifying states is explored, which is controlled by a small variation of two driving or probe radiations and does not require any change of the level populations. Optimum conditions for inversionless amplification of short-wavelength radiation above the oscillation threshold at the expense of the longer-wavelength control fields are investigated. The feasibility of overcoming the fundamental limitation on a velocity-interval of resonantly coupled molecules imposed by the Doppler effect is shown, based on quantum coherence.

  8. Femtosecond all-optical synchronization of an X-ray free-electron laser

    SciTech Connect

    Schulz, S.; Grguraš, I.; Behrens, C.; Bromberger, H.; Costello, J. T.; Czwalinna, M. K.; Felber, M.; Hoffmann, M. C.; Ilchen, M.; Liu, H. Y.; Mazza, T.; Meyer, M.; Pfeiffer, S.; Prędki, P.; Schefer, S.; Schmidt, C.; Wegner, U.; Schlarb, H.; Cavalieri, A. L.

    2015-01-20

    Many advanced applications of X-ray free-electron lasers require pulse durations and time resolutions of only a few femtoseconds. To generate these pulses and to apply them in time-resolved experiments, synchronization techniques that can simultaneously lock all independent components, including all accelerator modules and all external optical lasers, to better than the delivered free-electron laser pulse duration, are needed. Here we achieve all-optical synchronization at the soft X-ray free-electron laser FLASH and demonstrate facility-wide timing to better than 30 fs r.m.s. for 90 fs X-ray photon pulses. Crucially, our analysis indicates that the performance of this optical synchronization is limited primarily by the free-electron laser pulse duration, and should naturally scale to the sub-10 femtosecond level with shorter X-ray pulses.

  9. Femtosecond all-optical synchronization of an X-ray free-electron laser

    PubMed Central

    Schulz, S.; Grguraš, I.; Behrens, C.; Bromberger, H.; Costello, J. T.; Czwalinna, M. K.; Felber, M.; Hoffmann, M. C.; Ilchen, M.; Liu, H. Y.; Mazza, T.; Meyer, M.; Pfeiffer, S.; Prędki, P.; Schefer, S.; Schmidt, C.; Wegner, U.; Schlarb, H.; Cavalieri, A. L.

    2015-01-01

    Many advanced applications of X-ray free-electron lasers require pulse durations and time resolutions of only a few femtoseconds. To generate these pulses and to apply them in time-resolved experiments, synchronization techniques that can simultaneously lock all independent components, including all accelerator modules and all external optical lasers, to better than the delivered free-electron laser pulse duration, are needed. Here we achieve all-optical synchronization at the soft X-ray free-electron laser FLASH and demonstrate facility-wide timing to better than 30 fs r.m.s. for 90 fs X-ray photon pulses. Crucially, our analysis indicates that the performance of this optical synchronization is limited primarily by the free-electron laser pulse duration, and should naturally scale to the sub-10 femtosecond level with shorter X-ray pulses. PMID:25600823

  10. Femtosecond all-optical synchronization of an X-ray free-electron laser.

    PubMed

    Schulz, S; Grguraš, I; Behrens, C; Bromberger, H; Costello, J T; Czwalinna, M K; Felber, M; Hoffmann, M C; Ilchen, M; Liu, H Y; Mazza, T; Meyer, M; Pfeiffer, S; Prędki, P; Schefer, S; Schmidt, C; Wegner, U; Schlarb, H; Cavalieri, A L

    2015-01-20

    Many advanced applications of X-ray free-electron lasers require pulse durations and time resolutions of only a few femtoseconds. To generate these pulses and to apply them in time-resolved experiments, synchronization techniques that can simultaneously lock all independent components, including all accelerator modules and all external optical lasers, to better than the delivered free-electron laser pulse duration, are needed. Here we achieve all-optical synchronization at the soft X-ray free-electron laser FLASH and demonstrate facility-wide timing to better than 30 fs r.m.s. for 90 fs X-ray photon pulses. Crucially, our analysis indicates that the performance of this optical synchronization is limited primarily by the free-electron laser pulse duration, and should naturally scale to the sub-10 femtosecond level with shorter X-ray pulses.

  11. 25th anniversary article: Design of polymethine dyes for all-optical switching applications: guidance from theoretical and computational studies.

    PubMed

    Gieseking, Rebecca L; Mukhopadhyay, Sukrit; Risko, Chad; Marder, Seth R; Brédas, Jean-Luc

    2014-01-08

    All-optical switching--controlling light with light--has the potential to meet the ever-increasing demand for data transmission bandwidth. The development of organic π-conjugated molecular materials with the requisite properties for all-optical switching applications has long proven to be a significant challenge. However, recent advances demonstrate that polymethine dyes have the potential to meet the necessary requirements. In this review, we explore the theoretical underpinnings that guide the design of π-conjugated materials for all-optical switching applications. We underline, from a computational chemistry standpoint, the relationships among chemical structure, electronic structure, and optical properties that make polymethines such promising materials.

  12. All-optical pulse-echo ultrasound probe for intravascular imaging (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Colchester, Richard J.; Noimark, Sacha; Mosse, Charles A.; Zhang, Edward Z.; Beard, Paul C.; Parkin, Ivan P.; Papakonstantinou, Ioannis; Desjardins, Adrien E.

    2016-02-01

    High frequency ultrasound probes such as intravascular ultrasound (IVUS) and intracardiac echocardiography (ICE) catheters can be invaluable for guiding minimally invasive medical procedures in cardiology such as coronary stent placement and ablation. With current-generation ultrasound probes, ultrasound is generated and received electrically. The complexities involved with fabricating these electrical probes can result in high costs that limit their clinical applicability. Additionally, it can be challenging to achieve wide transmission bandwidths and adequate wideband reception sensitivity with small piezoelectric elements. Optical methods for transmitting and receiving ultrasound are emerging as alternatives to their electrical counterparts. They offer several distinguishing advantages, including the potential to generate and detect the broadband ultrasound fields (tens of MHz) required for high resolution imaging. In this study, we developed a miniature, side-looking, pulse-echo ultrasound probe for intravascular imaging, with fibre-optic transmission and reception. The axial resolution was better than 70 microns, and the imaging depth in tissue was greater than 1 cm. Ultrasound transmission was performed by photoacoustic excitation of a carbon nanotube/polydimethylsiloxane composite material; ultrasound reception, with a fibre-optic Fabry-Perot cavity. Ex vivo tissue studies, which included healthy swine tissue and diseased human tissue, demonstrated the strong potential of this technique. To our knowledge, this is the first study to achieve an all-optical pulse-echo ultrasound probe for intravascular imaging. The potential for performing all-optical B-mode imaging (2D and 3D) with virtual arrays of transmit/receive elements, and hybrid imaging with pulse-echo ultrasound and photoacoustic sensing are discussed.

  13. OptoDyCE: Automated system for high-throughput all-optical dynamic cardiac electrophysiology

    NASA Astrophysics Data System (ADS)

    Klimas, Aleksandra; Yu, Jinzhu; Ambrosi, Christina M.; Williams, John C.; Bien, Harold; Entcheva, Emilia

    2016-02-01

    In the last two decades, <30% of drugs withdrawals from the market were due to cardiac toxicity, where unintended interactions with ion channels disrupt the heart's normal electrical function. Consequently, all new drugs must undergo preclinical testing for cardiac liability, adding to an already expensive and lengthy process. Recognition that proarrhythmic effects often result from drug action on multiple ion channels demonstrates a need for integrative and comprehensive measurements. Additionally, patient-specific therapies relying on emerging technologies employing stem-cell derived cardiomyocytes (e.g. induced pluripotent stem-cell-derived cardiomyocytes, iPSC-CMs) require better screening methods to become practical. However, a high-throughput, cost-effective approach for cellular cardiac electrophysiology has not been feasible. Optical techniques for manipulation and recording provide a contactless means of dynamic, high-throughput testing of cells and tissues. Here, we consider the requirements for all-optical electrophysiology for drug testing, and we implement and validate OptoDyCE, a fully automated system for all-optical cardiac electrophysiology. We demonstrate the high-throughput capabilities using multicellular samples in 96-well format by combining optogenetic actuation with simultaneous fast high-resolution optical sensing of voltage or intracellular calcium. The system can also be implemented using iPSC-CMs and other cell-types by delivery of optogenetic drivers, or through the modular use of dedicated light-sensitive somatic cells in conjunction with non-modified cells. OptoDyCE provides a truly modular and dynamic screening system, capable of fully-automated acquisition of high-content information integral for improved discovery and development of new drugs and biologics, as well as providing a means of better understanding of electrical disturbances in the heart.

  14. Ultrafast all-optical arithmetic logic based on hydrogenated amorphous silicon microring resonators

    NASA Astrophysics Data System (ADS)

    Gostimirovic, Dusan; Ye, Winnie N.

    2016-03-01

    For decades, the semiconductor industry has been steadily shrinking transistor sizes to fit more performance into a single silicon-based integrated chip. This technology has become the driving force for advances in education, transportation, and health, among others. However, transistor sizes are quickly approaching their physical limits (channel lengths are now only a few silicon atoms in length), and Moore's law will likely soon be brought to a stand-still despite many unique attempts to keep it going (FinFETs, high-k dielectrics, etc.). This technology must then be pushed further by exploring (almost) entirely new methodologies. Given the explosive growth of optical-based long-haul telecommunications, we look to apply the use of high-speed optics as a substitute to the digital model; where slow, lossy, and noisy metal interconnections act as a major bottleneck to performance. We combine the (nonlinear) optical Kerr effect with a single add-drop microring resonator to perform the fundamental AND-XOR logical operations of a half adder, by all-optical means. This process is also applied to subtraction, higher-order addition, and the realization of an all-optical arithmetic logic unit (ALU). The rings use hydrogenated amorphous silicon as a material with superior nonlinear properties to crystalline silicon, while still maintaining CMOS-compatibility and the many benefits that come with it (low cost, ease of fabrication, etc.). Our method allows for multi-gigabit-per-second data rates while maintaining simplicity and spatial minimalism in design for high-capacity manufacturing potential.

  15. All-Optical Micro Motors Based on Moving Gratings in Photosensitive Media

    NASA Technical Reports Server (NTRS)

    Adamovsky, Gregory (Technical Monitor); Curley, M.; Sarkisov, S.; Fields, A.

    2003-01-01

    This research effort was a feasibility study of the concept of an all-optical micro motor with a rotor driven by a traveling wave. The wave was a result of a photo induced surface deformation of a photosensitive material produced by a traveling holographic grating. Two phases modulated coherent optical beams were used to generate the grating in two types of photosensitive materials. The materials that were studied were photorefractive crystals and thin polymer films. Theoretical studies were performed on lithium niobate giving predictions of deformations of the order of nanometers. The experimental deformation size was also on the order of nanometers. The deformations were deep enough to provide conditions for the implementation of the all-optical motor using lithium niobate. We also were able to align micron-size dielectric particles along the holographic gratings by means of the periodic electric forces generated by the grating. These forces can also move the particles along the surface if the grating is moving. We then turned our attention on thin films and obtained a deformation visible on the order of 100 microns. An experimental breadboard demonstration of a prototype was done in the summer of 2001 at Glenn Research Center (GRC). The demonstration included the movement of clocks mechanical workings by an optically driven motor based on a polymer film. The application of this technology can be adapted to government as well as industrial uses. One such project is to make a chemical sensor for the detection of hazardous chemicals. The thin polymer film is highly suited for this purpose since a marker dye could be easily placed on the film in order to detect chemical compounds. This system could be a self-regulating chemical monitoring system used on launches of the space shuttle or locations where hazardous chemicals are present. The project provided support for two black minority graduate students targeting MS and PhD degrees in Applied Optics.

  16. High efficiency 160 Gb/s all-optical wavelength converter based on terahertz optical asymmetric demultiplexer with quantum dot semiconductor optical amplifier

    NASA Astrophysics Data System (ADS)

    Han, Huining; Zhang, Fangdi; Yang, Wei; Cai, Libo; Zhang, Min; Ye, Peida

    2007-11-01

    Proposed in this paper is a high efficient 160Gb/s all-optical wavelength converter based on terahertz optical asymmetric demultiplexer with quantum dot Semiconductor optical amplifier (QDSOA -TOAD). The performance of the wavelength converter under various operating conditions, such as different injected current densities, input pulse widths and input control pulse energies, is analyzed in terms of contrast ratio (CR) through numerical simulations. With the properly chosen parameters, a wavelength-converted signal with CR over 19.48 can be obtained.

  17. Microwave hydrology: A trilogy

    NASA Technical Reports Server (NTRS)

    Stacey, J. M.; Johnston, E. J.; Girard, M. A.; Regusters, H. A.

    1985-01-01

    Microwave hydrology, as the term in construed in this trilogy, deals with the investigation of important hydrological features on the Earth's surface as they are remotely, and passively, sensed by orbiting microwave receivers. Microwave wavelengths penetrate clouds, foliage, ground cover, and soil, in varying degrees, and reveal the occurrence of standing liquid water on and beneath the surface. The manifestation of liquid water appearing on or near the surface is reported by a microwave receiver as a signal with a low flux level, or, equivalently, a cold temperature. Actually, the surface of the liquid water reflects the low flux level from the cosmic background into the input terminals of the receiver. This trilogy describes and shows by microwave flux images: the hydrological features that sustain Lake Baykal as an extraordinary freshwater resource; manifestations of subsurface water in Iran; and the major water features of the Congo Basin, a rain forest.

  18. Low threshold all-optical crossbar switch on GaAs-GaAlAs channel waveguide arrays

    NASA Astrophysics Data System (ADS)

    Jannson, Tomasz; Kostrzewski, Andrew

    1994-09-01

    During the Phase 2 project entitled 'Low Threshold All-Optical Crossbar Switch on GaAs - GaAlAs Channel Waveguide Array,' Physical Optics Corporation (POC) developed the basic principles for the fabrication of all-optical crossbar switches. Based on this development. POC fabricated a 2 x 2 GaAs/GaAlAs switch that changes the direction of incident light with minimum insertion loss and nonlinear distortion. This unique technology can be used in both analog and digital networks. The applications of this technology are widespread. Because the all-optical network does not have any speed limitations (RC time constant), POC's approach will be beneficial to SONET networks, phased array radar networks, very high speed oscilloscopes, all-optical networks, IR countermeasure systems, BER equipment, and the fast growing video conferencing network market. The novel all-optical crossbar switch developed in this program will solve interconnect problems. and will be a key component in the widely proposed all-optical 200 Gb/s SONET/ATM networks.

  19. All-optical OFDM transmitter design using AWGRs and low-bandwidth modulators

    NASA Astrophysics Data System (ADS)

    Lowery, Arthur James; Du, Liang

    2011-08-01

    An Arrayed-Waveguide Grating Router (AWGR) can be used as a demultiplexer for an optical OFDM system, as it provides both the serial-to-parallel converter and the optical Fourier transform (FT) in one component. Because an inverse FT is topologically identical to a Fourier transform, the AWGR can also be used as a FT in an OFDM transmitter. In most all-optical OFDM systems the optical modulators are fed with CW tones; however, the subcarriers (SC) will only be perfectly orthogonal if the bandwidth of the data modulators is similar to the total bandwidth of all subcarriers. Using simulations, this paper investigates the reduction in modulator bandwidth that could be achieved if the modulators are placed before an AWGR designed as a FT. This arrangement also allows the complex (IQ) modulators to be replaced with simpler and more-compact phase modulators. We show that these design improvements enable 7.5-GHz bandwidth modulators to be used in a 4 - 10 Gsymbol/s (80 Gbit/s) per polarization per wavelength system.

  20. Ultra fast all-optical fiber pressure sensor for blast event evaluation

    NASA Astrophysics Data System (ADS)

    Wu, Nan; Wang, Wenhui; Tian, Ye; Niezrecki, Christopher; Wang, Xingwei

    2011-05-01

    Traumatic brain injury (TBI) is a great potential threat to soldiers who are exposed to explosions or athletes who receive cranial impacts. Protecting people from TBI has recently attracted a significant amount of attention due to recent military operations in the Middle East. Recording pressure transient data in a blast event is very critical to the understanding of the effects of blast events on TBI. However, due to the fast change of the pressure during blast events, very few sensors have the capability to effectively track the dynamic pressure transients. This paper reports an ultra fast, miniature and all-optical fiber pressure sensor which could be mounted at different locations of a helmet to measure the fast changing pressure simultaneously. The sensor is based on Fabry-Perot (FP) principle. The end face of the fiber is wet etched. A well controlled thickness silicon dioxide diaphragm is thermal bonded on the end face to form an FP cavity. A shock tube test was conducted at Natick Soldier Research Development and Engineering Center, where the sensors were mounted in a shock tube side by side with a reference sensor to measure the rapidly changing pressure. The results of the test demonstrated that the sensor developed had an improved rise time (shorter than 0.4 μs) when compared to a commercially available reference sensor.

  1. Continuous all-optical deceleration and single-photon cooling of molecular beams

    NASA Astrophysics Data System (ADS)

    Jayich, A. M.; Vutha, A. C.; Hummon, M. T.; Porto, J. V.; Campbell, W. C.

    2014-02-01

    Ultracold molecular gases are promising as an avenue to rich many-body physics, quantum chemistry, quantum information, and precision measurements. This richness, which flows from the complex internal structure of molecules, makes the creation of ultracold molecular gases using traditional methods (laser plus evaporative cooling) a challenge, in particular due to the spontaneous decay of molecules into dark states. We propose a way to circumvent this key bottleneck using an all-optical method for decelerating molecules using stimulated absorption and emission with a single ultrafast laser. We further describe single-photon cooling of the decelerating molecules that exploits their high dark state pumping rates, turning the principal obstacle to molecular laser cooling into an advantage. Cooling and deceleration may be applied simultaneously and continuously to load molecules into a trap. We discuss implementation details including multilevel numerical simulations of strontium monohydride. These techniques are applicable to a large number of molecular species and atoms with the only requirement being an electric dipole transition that can be accessed with an ultrafast laser.

  2. Superstructures of chiral nematic microspheres as all-optical switchable distributors of light

    PubMed Central

    Aβhoff, Sarah J.; Sukas, Sertan; Yamaguchi, Tadatsugu; Hommersom, Catharina A.; Le Gac, Séverine; Katsonis, Nathalie

    2015-01-01

    Light technology is based on generating, detecting and controlling the wavelength, polarization and direction of light. Emerging applications range from electronics and telecommunication to health, defence and security. In particular, data transmission and communication technologies are currently asking for increasingly complex and fast devices, and therefore there is a growing interest in materials that can be used to transmit light and also to control the distribution of light in space and time. Here, we design chiral nematic microspheres whose shape enables them to reflect light of different wavelengths and handedness in all directions. Assembled in organized hexagonal superstructures, these microspheres of well-defined sizes communicate optically with high selectivity for the colour and chirality of light. Importantly, when the microspheres are doped with photo-responsive molecular switches, their chiroptical communication can be tuned, both gradually in wavelength and reversibly in polarization. Since the kinetics of the “on” and “off” switching can be adjusted by molecular engineering of the dopants and because the photonic cross-communication is selective with respect to the chirality of the incoming light, these photo-responsive microspheres show potential for chiroptical all-optical distributors and switches, in which wavelength, chirality and direction of the reflected light can be controlled independently and reversibly. PMID:26400584

  3. All-optical bidirectional neural interfacing using hybrid multiphoton holographic optogenetic stimulation

    PubMed Central

    Paluch-Siegler, Shir; Mayblum, Tom; Dana, Hod; Brosh, Inbar; Gefen, Inna; Shoham, Shy

    2015-01-01

    Abstract. Our understanding of neural information processing could potentially be advanced by combining flexible three-dimensional (3-D) neuroimaging and stimulation. Recent developments in optogenetics suggest that neurophotonic approaches are in principle highly suited for noncontact stimulation of network activity patterns. In particular, two-photon holographic optical neural stimulation (2P-HONS) has emerged as a leading approach for multisite 3-D excitation, and combining it with temporal focusing (TF) further enables axially confined yet spatially extended light patterns. Here, we study key steps toward bidirectional cell-targeted 3-D interfacing by introducing and testing a hybrid new 2P-TF-HONS stimulation path for accurate parallel optogenetic excitation into a recently developed hybrid multiphoton 3-D imaging system. The system is shown to allow targeted all-optical probing of in vitro cortical networks expressing channelrhodopsin-2 using a regeneratively amplified femtosecond laser source tuned to 905 nm. These developments further advance a prospective new tool for studying and achieving distributed control over 3-D neuronal circuits both in vitro and in vivo. PMID:26217673

  4. All-Optical Chirality-Sensitive Sorting via Reversible Lateral Forces in Interference Fields.

    PubMed

    Zhang, Tianhang; Mahdy, Mahdy Rahman Chowdhury; Liu, Yongmin; Teng, Jing Hua; Lim, Chwee Teck; Wang, Zheng; Qiu, Cheng-Wei

    2017-04-05

    Separating substances by their chirality faces great challenges as well as opportunities in chemistry and biology. In this study, we propose an all-optical solution for passive sorting of chiral objects using chirality-dependent lateral optical forces induced by judiciously interfered fields. First, we investigate the optical forces when the chiral objects are situated in the interference field formed by two plane waves with arbitrary polarization states. When the plane waves are either linearly or circularly polarized, nonzero lateral forces are found at the particle's trapping positions, making such sideways motions observable. Although the lateral forces have different magnitudes on particles with different chirality, their directions are the same for opposite handedness particles, rendering it difficult to separate the chiral particles. We further solve the sorting problem by investigating more complicated polarization states. Finally, we achieve the chiral-selective separation by illuminating only one beam toward the chiral substance situated at an interface between two media, taking advantage of the native interference between the incident and reflective beams at the interface. Our study provides a robust and insightful approach to sort chiral substances and biomolecules with plausible optical setups.

  5. A polyimide-etalon thin film structure for all-optical high-frequency ultrasound transduction.

    PubMed

    Sheaff, Clay; Ashkenazi, Shai

    2012-10-01

    In this work, we have designed, fabricated, and tested an all-optical ultrasound transducer by integrating a photoabsorptive polyimide thin film into a Fabry-Pérot (etalon) high-frequency receiver. A 5-ns UV pulse was used for thermoelastic ultrasound generation in the polyimide film, and the transmission had a maximum amplitude of 4.3 MPa centered at 27 MHz with a fractional bandwidth of 107%. The device attained a noise-equivalent pressure of 1.3 Pa/√Hz in receive-only mode. When used in pulse-echo mode, the -6-dB upper cutoff frequency of the transmit/receive response reached 47 MHz. Basic imaging capabilities were also investigated by scanning the near-infrared probe beam across the device to create a 2 × 2 mm synthetic aperture. The imaging of targets placed at depths of 1.8 and 5.2 mm yielded estimates of 71 and 145 μm, respectively, for the lateral resolution and 35 and 38 μm, respectively, for the axial resolution. Finally, a design concept for a forward-viewing intravascular imager is presented that entails the coupling of light to a rotating, linear array of optical fibers on top of which are deposited polyimide-etalon transducers. Such a design would allow for a flexible and compact high-resolution imager well-suited for intravascular applications, such as guidance of treatment in the case of chronic total occlusion.

  6. All-optical fiber anemometer based on laser heated fiber Bragg gratings.

    PubMed

    Gao, Shaorui; Zhang, A Ping; Tam, Hwa-Yaw; Cho, L H; Lu, Chao

    2011-05-23

    A fiber-optic anemometer based on fiber Bragg gratings (FBGs) is presented. A short section of cobalt-doped fiber was utilized to make a fiber-based "hot wire" for wind speed measurement. Fiber Bragg gratings (FBGs) were fabricated in the cobalt-doped fiber using 193 nm laser pulses to serve as localized temperature sensors. A miniature all-optical fiber anemometer is constructed by using two FBGs to determine the dynamic thermal equilibrium between the laser heating and air flow cooling through monitoring the FBGs' central wavelengths. It was demonstrated that the sensitivity of the sensor can be adjusted through the power of pump laser or the coating on the FBG. Experimental results reveal that the proposed FBG-based anemometer exhibits very good performance for wind speed measurement. The resolution of the FBG-based anemometer is about 0.012 m/s for wind speed range between 2.0 m/s and 8.0 m/s.

  7. Fast all-optical nuclear spin echo technique based on EIT

    NASA Astrophysics Data System (ADS)

    Walther, Andreas; Nilsson, Adam N.; Li, Qian; Rippe, Lars; Kröll, Stefan

    2016-08-01

    We demonstrate an all-optical Raman spin echo technique, using electromagnetically induced transparency (EIT) to create the pulses required for a spin echo sequence: initialization, pi-rotation, and readout. The first pulse of the sequence induces coherence directly from a mixed state, and the technique is used to measure the nuclear spin coherence of an inhomogeneously broadened ensemble of rare-earth ions (Pr3 +) in a crystal. The rephasing pi-rotation is shown to offer an advantage of combining the rephasing action with the operation of a phase gate, particularly useful in e.g. dynamic decoupling sequences. In contrast to many previous experiments the sequence does not require any preparatory hole burning, which greatly shortens the total duration of the sequence. The effect of the different pulses is characterized by quantum state tomography and compared with simulations. We demonstrate two applications of the technique: compensating the magnetic field across our sample by monitoring T 2 reductions from stray magnetic fields, and measuring coherence times at temperatures up to 11 K, where standard preparation techniques are difficult to implement. We explore the potential of the technique, in particular for systems with much shorter T 2, and other possible applications.

  8. Manipulation of entanglement sudden death in an all-optical setup

    NASA Astrophysics Data System (ADS)

    Singh, Ashutosh; Pradyumna, Siva; Rau, A. R. P.; Sinha, Urbasi

    2017-03-01

    The unavoidable and irreversible interaction between an entangled quantum system and its environment causes decoherence of the individual qubits as well as degradation of the entanglement between them. Entanglement sudden death (ESD) is the phenomenon wherein disentanglement happens in finite time even when individual qubits decohere only asymptotically in time due to noise. Prolonging the entanglement is essential for the practical realization of entanglement-based quantum information and computation protocols. For this purpose, the local NOT operation in the computational basis on one or both qubits has been proposed. Here, we formulate an all-optical experimental set-up involving such NOT operations that can hasten, delay, or completely avert ESD, all depending on when it is applied during the process of decoherence. Analytical expressions for these are derived in terms of parameters of the initial state's density matrix, whether for pure or mixed entangled states. After a discussion of the schematics of the experiment, the problem is theoretically analyzed, and simulation results of such manipulations of ESD are presented.

  9. Rapid, all-optical crystal orientation imaging of two-dimensional transition metal dichalcogenide monolayers

    SciTech Connect

    David, Sabrina N.; Zhai, Yao; Zande, Arend M. van der; O'Brien, Kevin; Huang, Pinshane Y.; Chenet, Daniel A.; Hone, James C.; Zhang, Xiang; Yin, Xiaobo

    2015-09-14

    Two-dimensional (2D) atomic materials such as graphene and transition metal dichalcogenides (TMDCs) have attracted significant research and industrial interest for their electronic, optical, mechanical, and thermal properties. While large-area crystal growth techniques such as chemical vapor deposition have been demonstrated, the presence of grain boundaries and orientation of grains arising in such growths substantially affect the physical properties of the materials. There is currently no scalable characterization method for determining these boundaries and orientations over a large sample area. We here present a second-harmonic generation based microscopy technique for rapidly mapping grain orientations and boundaries of 2D TMDCs. We experimentally demonstrate the capability to map large samples to an angular resolution of ±1° with minimal sample preparation and without involved analysis. A direct comparison of the all-optical grain orientation maps against results obtained by diffraction-filtered dark-field transmission electron microscopy plus selected-area electron diffraction on identical TMDC samples is provided. This rapid and accurate tool should enable large-area characterization of TMDC samples for expedited studies of grain boundary effects and the efficient characterization of industrial-scale production techniques.

  10. All-Optical dc Nanotesla Magnetometry Using Silicon Vacancy Fine Structure in Isotopically Purified Silicon Carbide

    NASA Astrophysics Data System (ADS)

    Simin, D.; Soltamov, V. A.; Poshakinskiy, A. V.; Anisimov, A. N.; Babunts, R. A.; Tolmachev, D. O.; Mokhov, E. N.; Trupke, M.; Tarasenko, S. A.; Sperlich, A.; Baranov, P. G.; Dyakonov, V.; Astakhov, G. V.

    2016-07-01

    We uncover the fine structure of a silicon vacancy in isotopically purified silicon carbide (4H-28SiC) and reveal not yet considered terms in the spin Hamiltonian, originated from the trigonal pyramidal symmetry of this spin-3 /2 color center. These terms give rise to additional spin transitions, which would be otherwise forbidden, and lead to a level anticrossing in an external magnetic field. We observe a sharp variation of the photoluminescence intensity in the vicinity of this level anticrossing, which can be used for a purely all-optical sensing of the magnetic field. We achieve dc magnetic field sensitivity better than 100 nT /√{Hz } within a volume of 3 ×10-7m m3 at room temperature and demonstrate that this contactless method is robust at high temperatures up to at least 500 K. As our approach does not require application of radio-frequency fields, it is scalable to much larger volumes. For an optimized light-trapping waveguide of 3 mm3 , the projection noise limit is below 100 fT /√{Hz } .

  11. Ultralow bias power all-optical photonic crystal memory realized with systematically tuned L3 nanocavity

    SciTech Connect

    Kuramochi, Eiichi Nozaki, Kengo; Shinya, Akihiko; Taniyama, Hideaki; Notomi, Masaya; Takeda, Koji; Matsuo, Shinji; Sato, Tomonari

    2015-11-30

    An InP photonic crystal nanocavity with an embedded InGaAsP active region is a unique technology that has realized an all-optical memory with a sub-micro-watt operating power and limitless storage time. In this study, we employed an L3 design with systematic multi-hole tuning, which realized a higher loaded Q factor (>40 000) and a lower mode volume (0.9 μm{sup 3}) than a line-defect-based buried-heterostructure nanocavity (16 000 and 2.2 μm{sup 3}). Excluding the active region realized a record loaded Q factor (210 000) in all for InP-based nanocavities. The minimum bias power for bistable memory operation was reduced to 2.3 ± 0.3 nW, which is about 1/10 of the previous record of 30 nW. This work further established the capability of a bistable nanocavity memory for use in future ultralow-power-consumption on-chip integrated photonics.

  12. Design of photonic crystal-based all-optical AND gate using T-shaped waveguide

    NASA Astrophysics Data System (ADS)

    haq Shaik, Enaul; Rangaswamy, Nakkeeran

    2016-05-01

    We present a new configuration of all-optical AND gate based on two-dimensional photonic crystal composed of Si rods in air. Two AND gate structures with and without probe input are proposed. The proposed structures are designed with T-shaped waveguide without using nonlinear materials and optical amplifiers. The performance of the proposed AND gate structures is analyzed and simulated by plane-wave expansion and finite difference time domain methods. The AND gate without probe input needs only one T-shaped waveguide, whereas the AND gate with probe input needs two T-shaped waveguides. The former AND gate offers a bit rate of 6.26 Tbps with a contrast ratio of 5.74 dB, whereas the latter AND gate offers a bit rate of 3.58 Tbps whose contrast ratio is 9.66 dB. It can be expected that these small size T-shaped structures are suitable for large-scale integration and can potentially be used in on-chip photonic integrated circuits.

  13. All optical experimental design for neuron excitation, inhibition, and action potential detection

    NASA Astrophysics Data System (ADS)

    Walsh, Alex J.; Tolstykh, Gleb; Martens, Stacey; Sedelnikova, Anna; Ibey, Bennett L.; Beier, Hope T.

    2016-03-01

    Recently, infrared light has been shown to both stimulate and inhibit excitatory cells. However, studies of infrared light for excitatory cell inhibition have been constrained by the use of invasive and cumbersome electrodes for cell excitation and action potential recording. Here, we present an all optical experimental design for neuronal excitation, inhibition, and action potential detection. Primary rat neurons were transfected with plasmids containing the light sensitive ion channel CheRiff. CheRiff has a peak excitation around 450 nm, allowing excitation of transfected neurons with pulsed blue light. Additionally, primary neurons were transfected with QuasAr2, a fast and sensitive fluorescent voltage indicator. QuasAr2 is excited with yellow or red light and therefore does not spectrally overlap CheRiff, enabling imaging and action potential activation, simultaneously. Using an optic fiber, neurons were exposed to blue light sequentially to generate controlled action potentials. A second optic fiber delivered a single pulse of 1869nm light to the neuron causing inhibition of the evoked action potentials (by the blue light). When used in concert, these optical techniques enable electrode free neuron excitation, inhibition, and action potential recording, allowing research into neuronal behaviors with high spatial fidelity.

  14. Strong coupling and high-contrast all-optical modulation in atomic cladding waveguides

    PubMed Central

    Stern, Liron; Desiatov, Boris; Mazurski, Noa; Levy, Uriel

    2017-01-01

    In recent years, there has been marked increase in research aimed to introduce alkali vapours into guided-wave configurations. Owing to the significant reduction in device dimensions, the increase in density of states, the interaction with surfaces and primarily the high intensities carried along the structure, a plethora of light–vapour interactions can be studied. Moreover, such platform may exhibit new functionalities such as low-power nonlinear light–matter interactions. One immense challenge is to study the effects of quantum coherence and shifts in nanoscale waveguides, characterized by ultra-small mode areas and fast dynamics. Here, we construct a highly compact 17 mm long serpentine silicon-nitride atomic vapour cladding waveguide. Fascinating and important phenomena such as van-der-Waals shifts, dynamical stark shifts and coherent effects such as strong coupling (in the form of Autler–Townes splitting) are observed. Some of these effects may play an important role in applications such as all-optical switching, frequency referencing and magnetometry. PMID:28181510

  15. Strong coupling and high-contrast all-optical modulation in atomic cladding waveguides

    NASA Astrophysics Data System (ADS)

    Stern, Liron; Desiatov, Boris; Mazurski, Noa; Levy, Uriel

    2017-02-01

    In recent years, there has been marked increase in research aimed to introduce alkali vapours into guided-wave configurations. Owing to the significant reduction in device dimensions, the increase in density of states, the interaction with surfaces and primarily the high intensities carried along the structure, a plethora of light-vapour interactions can be studied. Moreover, such platform may exhibit new functionalities such as low-power nonlinear light-matter interactions. One immense challenge is to study the effects of quantum coherence and shifts in nanoscale waveguides, characterized by ultra-small mode areas and fast dynamics. Here, we construct a highly compact 17 mm long serpentine silicon-nitride atomic vapour cladding waveguide. Fascinating and important phenomena such as van-der-Waals shifts, dynamical stark shifts and coherent effects such as strong coupling (in the form of Autler-Townes splitting) are observed. Some of these effects may play an important role in applications such as all-optical switching, frequency referencing and magnetometry.

  16. High-Throughput All-Optical Analysis of Synaptic Transmission and Synaptic Vesicle Recycling in Caenorhabditis elegans

    PubMed Central

    Wabnig, Sebastian; Liewald, Jana Fiona; Yu, Szi-chieh; Gottschalk, Alexander

    2015-01-01

    Synaptic vesicles (SVs) undergo a cycle of biogenesis and membrane fusion to release transmitter, followed by recycling. How exocytosis and endocytosis are coupled is intensively investigated. We describe an all-optical method for identification of neurotransmission genes that can directly distinguish SV recycling factors in C. elegans, by motoneuron photostimulation and muscular RCaMP Ca2+ imaging. We verified our approach on mutants affecting synaptic transmission. Mutation of genes affecting SV recycling (unc-26 synaptojanin, unc-41 stonin, unc-57 endophilin, itsn-1 intersectin, snt-1 synaptotagmin) showed a distinct ‘signature’ of muscle Ca2+ dynamics, induced by cholinergic motoneuron photostimulation, i.e. faster rise, and earlier decrease of the signal, reflecting increased synaptic fatigue during ongoing photostimulation. To facilitate high throughput, we measured (3–5 times) ~1000 nematodes for each gene. We explored if this method enables RNAi screening for SV recycling genes. Previous screens for synaptic function genes, based on behavioral or pharmacological assays, allowed no distinction of the stage of the SV cycle in which a protein might act. We generated a strain enabling RNAi specifically only in cholinergic neurons, thus resulting in healthier animals and avoiding lethal phenotypes resulting from knockdown elsewhere. RNAi of control genes resulted in Ca2+ measurements that were consistent with results obtained in the respective genomic mutants, albeit to a weaker extent in most cases, and could further be confirmed by opto-electrophysiological measurements for mutants of some of the genes, including synaptojanin. We screened 95 genes that were previously implicated in cholinergic transmission, and several controls. We identified genes that clustered together with known SV recycling genes, exhibiting a similar signature of their Ca2+ dynamics. Five of these genes (C27B7.7, erp-1, inx-8, inx-10, spp-10) were further assessed in respective

  17. All-optical modulation format conversion from NRZ-OOK to RZ-QPSK using parallel SOA-MZI OOK/BPSK converters.

    PubMed

    Mishina, Ken; Nissanka, Suresh M; Maruta, Akihiro; Mitani, Shunsuke; Ishida, Kazuyuki; Shimizu, Katsuhiro; Hatta, Tatsuo; Kitayama, Ken-Ichi

    2007-06-11

    A novel all-optical modulation format conversion from non-return-to-zero on-off-keying (NRZ-OOK) to return-to-zero quadrature-phase-shift-keying (RZ-QPSK) is proposed and experimentally demonstrated. The proposed format conversion scheme is based on parallel Mach-Zehnder interferometric (MZI) OOK/binary-PSK (BPSK) converters, consisting of integrated semiconductor optical amplifiers (SOAs). We experimentally demonstrate that in both decoded channels of the converted RZ-QPSK signal bit error rate (BER) curves show almost the same receiver sensitivity at a symbol-rate of 10.7 Gsymbol/s. In addition, a reasonable dispersion tolerance of the converted signal up to +295 ps/nm is observed. The numerical simulation based upon carrier rate equation verifies the experimental results.

  18. Energy-efficient 0.26-Tb/s coherent-optical OFDM transmission using photonic-integrated all-optical discrete Fourier transform.

    PubMed

    Kang, I; Liu, X; Chandrasekhar, S; Rasras, M; Jung, H; Cappuzzo, M; Gomez, L T; Chen, Y F; Buhl, L; Cabot, S; Jaques, J

    2012-01-16

    We propose a novel energy-efficient coherent-optical OFDM transmission scheme based on hybrid optical-electronic signal processing. We demonstrate transmission of a 0.26-Tb/s OFDM superchannel, consisting of 13 x 20-Gb/s polarization-multiplexed QPSK subcarrier channels, over 400-km standard single-mode fiber (SSMF) with BER less than 6.3x10(-4) using all-optical Fourier transform processing and electronic 7-tap blind digital equalization per subchannel. We further explore long-haul transmission over up to 960 km SSMF and show that the electronic signal processing is capable of compensating chromatic dispersion up to 16,000 ps/nm using only 15 taps per subchannel, even in the presence of strong inter-carrier interference.

  19. 10 and 20 Gb/s all-optical RZ to NRZ modulation format and wavelength converter based on nonlinear optical loop mirror

    NASA Astrophysics Data System (ADS)

    Honzatko, Pavel; Karásek, Miroslav

    2010-05-01

    We present experimental and theoretical results on all-optical 10 and 20 Gb/s RZ to NRZ modulation format and wavelength converter based on a nonlinear optical loop mirror (NOLM). A vector model of converter was developed and the shape of converted pulses was found analytically for particular choice of polarization states. In the experiment, non-zero dispersion shifted fiber with a length 1200 m was used as a nonlinear medium. Pulses from a 10 GHz mode-locked semiconductor laser diode were modulated to form pseudorandom RZ signal and eventually time division multiplexed to 20 Gb/s. RZ pulses were subsequently converted to NRZ signal. The performance of the converter was evaluated experimentally using the data communication analyzer and bit error ratio tester.

  20. All-optical radiation reaction in head-on laser electron interaction

    NASA Astrophysics Data System (ADS)

    Vranic, Marija; Grismayer, Thomas; Martins, Joana L.; Fonseca, Ricardo A.; Silva, Luis O.

    2016-10-01

    Radiation reaction (RR) accounts for the slowdown of a charged particle that occurs when a significant fraction of its kinetic energy is emitted as radiation. Here we show that this effect could be measured in an all-optical setup using a laser wakefield accelerated electron beam colliding with an intense laser pulse. We employ full-scale 3D PIC simulations to show that one can enter a radiation reaction dominated regime with a GeV electron beam and a 30 fs laser of I = 1021W/cm2. The electrons can lose up to 40% of their initial energy, which can be used as an experimental signature in the spectra. Our results indicate that modern laser facilities provide an exciting opportunity to explore classical RR and the near-future laser facilities can be employed to study the RR beyond classical description. By using higher laser intensities (1022-1023W/cm2) , quantum effects such as Compton scattering and Breit-Wheeler pair production become relevant. We have included these quantum effects in our PIC code OSIRIS through a Monte Carlo module, and performed a detailed numerical study of the transition from classical to quantum RR dominated regime. We identified the distinct features in the electron distribution function that could serve as signatures of quantum radiation reaction, and showed that large-scale infrastructures (e.g. NIF and ELI and next generation of PW-class lasers (e. g. CoReLS, Bella-i, Texas Petawatt, Apollon 10 PW) could be employed to test the physics in these extreme scenarios.

  1. All-optical devices realized by the post-growth processing of multiquantum-well structures

    NASA Astrophysics Data System (ADS)

    LiKamWa, Patrick; Kan'an, Ayman M.; Dutta, Mitra; Pamulapati, Jagadeesh

    1997-01-01

    An inexpensive and reliable process for the area-selective disordering of MQW structures is reported. The method relies on the diffusion, by rapid thermal annealing, of surface vacancies into the quantum wells thereby intermixing the Ga and Al atoms between the wells and barriers. A silicon oxide cap that is formed by curing a spun-on solution of glass forming compound acts as porous layer that enhances the formation of surface vacancies by allowing out-diffusion of Ga and Al atoms. This technique has been applied to the fabrication of two integrated optical devices. One is the nonlinear zero-gap directional coupler with disordered input and output branching waveguides, and the other is the symmetric nonlinear integrated Mach-Zehnder interferometer with one arm containing a non-intermixed MQW section. In both devices, the mechanism for the switching is the nonlinear refractive index that is caused by photo-generated carriers. Since this mechanism entails absorption of some of the pump beam, it is hence very important that the optical absorption be confined to the active sections only. Selective area disordering is shown to be very effective at defining regions of different bandgap energies. Hence it can be ensured that the energy of the pump laser beam is too low in comparison to the bandgap energy of the passive regions to be absorbed and the free carriers are only created in the non-intermixed active sections. The devices investigated using a pump-probe setup, exhibited strong all-optical switching behavior with a contrast ratio of better than 7:1. The controlled selective area intermixing of MQW structures will potentially play a significant role in the advancement of photonic integrated circuits.

  2. Controllable vacuum-induced diffraction of matter-wave superradiance using an all-optical dispersive cavity

    PubMed Central

    Su, Shih-Wei; Lu, Zhen-Kai; Gou, Shih-Chuan; Liao, Wen-Te

    2016-01-01

    Cavity quantum electrodynamics (CQED) has played a central role in demonstrating the fundamental principles of the quantum world, and in particular those of atom-light interactions. Developing fast, dynamical and non-mechanical control over a CQED system is particularly desirable for controlling atomic dynamics and building future quantum networks at high speed. However conventional mirrors do not allow for such flexible and fast controls over their coupling to intracavity atoms mediated by photons. Here we theoretically investigate a novel all-optical CQED system composed of a binary Bose-Einstein condensate (BEC) sandwiched by two atomic ensembles. The highly tunable atomic dispersion of the CQED system enables the medium to act as a versatile, all-optically controlled atomic mirror that can be employed to manipulate the vacuum-induced diffraction of matter-wave superradiance. Our study illustrates a innovative all-optical element of atomtroics and sheds new light on controlling light-matter interactions. PMID:27748413

  3. Controllable vacuum-induced diffraction of matter-wave superradiance using an all-optical dispersive cavity

    NASA Astrophysics Data System (ADS)

    Su, Shih-Wei; Lu, Zhen-Kai; Gou, Shih-Chuan; Liao, Wen-Te

    2016-10-01

    Cavity quantum electrodynamics (CQED) has played a central role in demonstrating the fundamental principles of the quantum world, and in particular those of atom-light interactions. Developing fast, dynamical and non-mechanical control over a CQED system is particularly desirable for controlling atomic dynamics and building future quantum networks at high speed. However conventional mirrors do not allow for such flexible and fast controls over their coupling to intracavity atoms mediated by photons. Here we theoretically investigate a novel all-optical CQED system composed of a binary Bose-Einstein condensate (BEC) sandwiched by two atomic ensembles. The highly tunable atomic dispersion of the CQED system enables the medium to act as a versatile, all-optically controlled atomic mirror that can be employed to manipulate the vacuum-induced diffraction of matter-wave superradiance. Our study illustrates a innovative all-optical element of atomtroics and sheds new light on controlling light-matter interactions.

  4. High contrast all-optical diode based on direction-dependent optical bistability within asymmetric ring cavity

    NASA Astrophysics Data System (ADS)

    Xia, Xiu-Wen; Zhang, Xin-Qin; Xu, Jing-Ping; Yang, Ya-Ping

    2016-08-01

    We propose a simple all-optical diode which is comprised of an asymmetric ring cavity containing a two-level atomic ensemble. Attributed to spatial symmetry breaking of the ring cavity, direction-dependent optical bistability is obtained in a classical bistable system. Therefore, a giant optical non-reciprocity is generated, which guarantees an all-optical diode with a high contrast up to 22 dB. Furthermore, its application as an all-optical logic AND gate is also discussed. Project supported by the National Natural Science Foundation of China (Grant Nos. 11274242, 11474221, and 11574229), the Joint Fund of the National Natural Science Foundation of China and the China Academy of Engineering Physics (Grant No. U1330203), and the National Key Basic Research Special Foundation of China (Grant Nos. 2011CB922203 and 2013CB632701).

  5. Handbook of microwave testing

    NASA Astrophysics Data System (ADS)

    Laverghetta, T. S.

    A description of microwave test equipment is presented, taking into account signal generators, signal detection/indicating devices, auxiliary testing devices, and microwave systems. Low power, medium power, high power, and peak power measurements are considered along with noise measurements, spectrum analyzer measurements, active testing, antenna measurements, and automatic testing. Attention is given to phase noise, Q measurements, the Time Domain Reflectometry (TDR) measurement, swept impedance, noise sources, noise meters, manual noise measurements, automatic noise figure measurements, gain, gain compression, intermodulation, the third order intercept, and questions of spectral purity.

  6. High-Sensitivity Microwave Optics.

    ERIC Educational Resources Information Center

    Nunn, W. M., Jr.

    1981-01-01

    Describes a 3.33-cm wavelength (9 GHz) microwave system that achieves a high overall signal sensitivity and a well-collimated beam with moderate-size equipment. The system has been used to develop microwave versions of the Michelson interferometer, Bragg reflector, Brewster's law and total internal reflection, and Young's interference experiment.…

  7. IST-LASAGNE: Towards All-Optical Label Swapping Employing Optical Logic Gates and Optical Flip-Flops

    NASA Astrophysics Data System (ADS)

    Ramos, F.; Kehayas, E.; Martinez, J. M.; Clavero, R.; Marti, J.; Stampoulidis, L.; Tsiokos, D.; Avramopoulos, H.; Zhang, J.; Holm-Nielsen, P. V.; Chi, N.; Jeppesen, P.; Yan, N.; Tafur Monroy, I.; Koonen, A. M. J.; Hill, M. T.; Liu, Y.; Dorren, H. J. S.; van Caenegem, R.; Colle, D.; Pickavet, M.; Rip Ti, B.

    2005-10-01

    The Information Society Technologies-all-optical LAbel SwApping employing optical logic Gates in NEtwork nodes (IST-LASAGNE) project aims at designing and implementing the first, modular, scalable, and truly all-optical photonic router capable of operating at 40 Gb/s. The results of the first project year are presented in this paper, with emphasis on the implementation of network node functionalities employing optical logic gates and optical flip-flops, as well as the definition of the network architecture and migration scenarios.

  8. Engineered materials for all-optical helicity-dependent magnetic switching

    NASA Astrophysics Data System (ADS)

    Fullerton, Eric

    2014-03-01

    The possibilities of manipulating magnetization without applied magnetic fields have attracted growing attention over the last fifteen years. The low-power manipulation of magnetization, preferably at ultra-short time scales, has become a fundamental challenge with implications for future magnetic information memory and storage technologies. Here we explore the optical manipulation of the magnetization of engineered materials and devices using 100 fs optical pulses. We demonstrate that all optical - helicity dependent switching (AO-HDS) can be observed not only in selected rare-earth transition-metal (RE-TM) alloy films but also in a much broader variety of materials, including alloys, multilayers, heterostructures and RE-free Co-Ir-based synthetic ferrimagnets. The discovery of AO-HDS in RE-free TM-based synthetic ferrimagnets can enable breakthroughs for numerous applications since it exploits materials that are currently used in magnetic data storage, memories and logic technologies. In addition, this materials study of AO-HDS offers valuable insight into the underlying mechanisms involved. Indeed the common denominator of the diverse structures showing AO-HDS in this study is that two ferromagnetic sub-lattices exhibit magnetization compensation (and therefore angular momentum compensation) at temperatures near or above room temperature. We are highlighting that compensation plays a major role and that this compensation can be established at the atomic level as in alloys but also over a larger nanometers scale as in the multilayers or in heterostructures. We will also discuss the potential to extend AO-HDS to new classes of magnetic materials. This work was done in collaboration with S. Mangin, M. Gottwald, C-H. Lambert, D. Steil, V. Uhlíř, L. Pang, M. Hehn, S. Alebrand, M. Cinchetti, G. Malinowski, Y. Fainman, and M. Aeschlimann. Supported by the ANR-10-BLANC-1005 ``Friends,'' a grant from the Advanced Storage Technology Consortium, Partner University Fund

  9. Proposal for all-optical switchable and tunable ultrawideband monocycle generation utilizing SOA wavelength conversion and time delay

    NASA Astrophysics Data System (ADS)

    Hu, Zhefeng; Xu, Jianhui; Hou, Min

    2017-03-01

    An all-optical ultrawideband monocycle generator based on wavelength conversion in a semiconductor optical amplifier (SOA) and optical tunable delay in an optical delay line (ODL) is proposed and simulated. The system achieves optically switchable in pulse polarity and tunable in both the pulsewidth and radio frequency (RF) spectrum.

  10. Performance analysis of an all-optical OFDM system in presence of non-linear phase noise.

    PubMed

    Hmood, Jassim K; Harun, Sulaiman W; Emami, Siamak D; Khodaei, Amin; Noordin, Kamarul A; Ahmad, Harith; Shalaby, Hossam M H

    2015-02-23

    The potential for higher spectral efficiency has increased the interest in all-optical orthogonal frequency division multiplexing (OFDM) systems. However, the sensitivity of all-optical OFDM to fiber non-linearity, which causes nonlinear phase noise, is still a major concern. In this paper, an analytical model for estimating the phase noise due to self-phase modulation (SPM), cross-phase modulation (XPM), and four-wave mixing (FWM) in an all-optical OFDM system is presented. The phase noise versus power, distance, and number of subcarriers is evaluated by implementing the mathematical model using Matlab. In order to verify the results, an all-optical OFDM system, that uses coupler-based inverse fast Fourier transform/fast Fourier transform without any nonlinear compensation, is demonstrated by numerical simulation. The system employs 29 subcarriers; each subcarrier is modulated by a 4-QAM or 16-QAM format with a symbol rate of 25 Gsymbol/s. The results indicate that the phase variance due to FWM is dominant over those induced by either SPM or XPM. It is also shown that the minimum phase noise occurs at -3 dBm and -1 dBm for 4-QAM and 16-QAM, respectively. Finally, the error vector magnitude (EVM) versus subcarrier power and symbol rate is quantified using both simulation and the analytical model. It turns out that both EVM results are in good agreement with each other.

  11. All-optical Photonic Oscillator with High-Q Whispering Gallery Mode Resonators

    NASA Technical Reports Server (NTRS)

    Savchenkov, Anatoliy A.; Matsko, Andrey B.; Strekalov, Dmitry; Mohageg, Makan; Iltchenko, Vladimir S.; Maleki, Lute

    2004-01-01

    We demonstrated low threshold optical photonic hyper-parametric oscillator in a high-Q 10(exp 10) CaF2 whispering gallery mode resonator which generates stable 8.5 GHz signal. The oscillations result from the resonantly enhanced four wave mixing occurring due to Kerr nonlinearity of the material.

  12. Systems performance comparison of three all-optical generation schemes for quasi-Nyquist WDM.

    PubMed

    Lowery, Arthur James; Xie, Yiwei; Zhu, Chen

    2015-08-24

    Orthogonal time division multiplexing (OrthTDM) interleaves sinc-shaped pulses to form a high baud-rate signal, with a rectangular spectrum suitable for multiplexing into a Nyquist WDM (N-WDM)-like signal. The problem with generating sinc-shaped pulses is that they theoretically have infinite durations, and even if time bounded for practical implementation, they still require a filter with a long impulse response, hence a large physical size. Previously a method of creating chirped-orthogonal frequency division multiplexing (OFDM) pulses with a chirped arrayed waveguide (AWG) filter, then converting them into interleaved quasi-sinc pulses using dispersive fiber (DF), has been proposed. This produces a signal with a wider spectrum than the equivalent N-WDM signal. We show that a modification to the scheme enables the spectral extent to be reduced for the same data rate. We then analyse the key factors in designing an OrthTDM transmitter, and relate these to the performance of a N-WDM system. We show that the modified transmitter reduces the required guard band between the N-WDM channels. We also simulate a simpler scheme using an unchirped finite-impulse response filter of similar size, which directly creates truncated-sinc pulses without needing a DF. This gives better system performance than either chirped scheme.

  13. Ultrafast all-optical switch with cross-phase modulation by area-selective ion implantation in InGaAs/AlAsSb coupled double quantum wells.

    PubMed

    Feng, Jijun; Akimoto, Ryoichi; Gozu, Shin-ichiro; Mozume, Teruo; Hasama, Toshifumi; Ishikawa, Hiroshi

    2012-12-10

    We have developed a compact gate switch with monolithic integration of all-optical cross-phase modulation (XPM) in a Mach-Zehnder interferometer (MZI). XPM is caused by intersubband transition (ISBT) in InGaAs/AlAsSb coupled double quantum wells (CDQWs) by area-selective silicon ion implantation and rapid thermal annealing (RTA). While injecting pump light through a transverse electric/transverse magnetic (TE/TM) beam combiner, XPM is induced in one MZI arm and gating operation can be realized. The RTA condition is optimized, and the sample is annealed at 780 °C for 8 s with an implantation dose of 5 × 10(13) cm(-2). Dependence of XPM efficiency on the length of the implanted mesa is also analyzed, and there exists an optimum implantation length to fulfill both high efficiency of ISBT modulation and low loss of the probe and pump signals.

  14. All-optical 40 Gbit/s data format conversion between RZ and NRZ using a fiber delay interferometer and a single SOA

    NASA Astrophysics Data System (ADS)

    Wang, Fei; Xu, Enming; Yu, Yu; Zhang, Yin

    2011-12-01

    We demonstrated experimentally 40 Gbit/s all-optical format conversions between return-to-zero (RZ) and nonreturn-to- zero (NRZ) using a fiber delay interferometer (FDI) and a single semiconductor optical amplifier (SOA). Firstly, 40 Gbit/s data format conversion from RZ to NRZ is realized using a FDI with temperature control and an optical bandpass filter (BPF). Then, 40 Gbit/s data format conversion from NRZ to RZ is implemented, using four-wave mixing (FWM) effect of SOA, by injecting synchronously NRZ signal and clock pulses into a single SOA. Presented method has some distinct advantages including multi-channel parallel processing, easy integration, convenient tuning, good stability, and so on, which has potential to be used in future optical networks that could combine wavelength division multiplexing (WDM) and optical time domain multiplexing (OTDM) transmission techniques.

  15. Analysis of spatial-temporal converters for all-optical communication links.

    PubMed

    Marom, D M; Sun, P C; Fainman, Y

    1998-05-10

    We analyze parallel-to-serial transmitters and serial-to-parallel receivers that use ultrashort optical pulses to increase the bandwidth of a fiber-optic communication link. This method relies on real-time holographic material for conversion of information between spatial and temporal frequencies. The analysis reveals that the temporal output of the pulses will consist of chirped pulses, which has been verified experimentally. When the signal pulses are transmitted along with a reference pulse, the distortions of the received signal, caused by dispersion and other factors in the fiber, are canceled because of the phase-conjugation property of the receiver. This self-referencing scheme simplifies the receiver structure and ensures perfect timing for the serial-to-parallel conversion.

  16. All-optical OFDM demultiplexing by spectral magnification and band-pass filtering.

    PubMed

    Palushani, E; Mulvad, H C Hansen; Kong, D; Guan, P; Galili, M; Oxenløwe, L K

    2014-01-13

    We propose a simple OFDM receiver allowing for the use of standard WDM receivers to receive spectrally advanced OFDM signals. We propose to spectrally magnify the optical-OFDM super-channels using a spectral telescope consisting of two time-lenses, which enables reduced inter-carrier-interference in subcarrier detection by simple band-pass filtering. A demonstration on an emulated 100 Gbit/s DPSK optical-OFDM channel shows improved sensitivities after 4-times spectral magnification.

  17. Thermally induced all-optical inverter and dynamic hysteresis loops in graphene oxide dispersions.

    PubMed

    Melle, Sonia; Calderón, Oscar G; Egatz-Gómez, Ana; Cabrera-Granado, E; Carreño, F; Antón, M A

    2015-11-01

    We experimentally study the temporal dynamics of amplitude-modulated laser beams propagating through a water dispersion of graphene oxide sheets in a fiber-to-fiber U-bench. Nonlinear refraction induced in the sample by thermal effects leads to both phase reversing of the transmitted signals and dynamic hysteresis in the input-output power curves. A theoretical model including beam propagation and thermal lensing dynamics reproduces the experimental findings.

  18. All-optical tunable group-velocity control of femtosecond pulse by quadratic nonlinear cascading interactions.

    PubMed

    Lu, Wenjie; Chen, Yuping; Miu, Lihong; Chen, Xianfeng; Xia, Yuxing; Zeng, Xianglong

    2008-01-07

    Based on cascading nonlinear interactions of second harmonic generation (SHG) and difference frequency generation (DFG), we present a novel scheme to control the group velocity of femtosecond pulse in MgO doped periodically poled lithium niobate crystal. Group velocity of tunable signal pulse can be controlled by another pump beam within a wide bandwidth of 180nm. Fractional advancement of 2.4 and fractional delay of 4 are obtained in our simulations.

  19. All-optical Integrated Switches Based on Azo-benzene Liquid Crystals on Silicon

    DTIC Science & Technology

    2011-11-01

    optical signal. The first consists of a commercial NLC mixture embedded in a SiO2/Si groove. The numerical simulation, obtained with an ad hoc model...substrates filled with NLC . With a particular glass surface treatment ( NLC alignment condition φ0) we can avoid the use of an external bias voltage, as in...director n̂ with tilt (θ) and twist (φ) angle. The waveguide structure, schematically illustrated in Fig. 1, consists of nematic LC ( NLC ) E7

  20. Demonstration and optimisation of an ultrafast all-optical AND logic gate using four-wave mixing in a semiconductor optical amplifier

    SciTech Connect

    Razaghi, M; Nosratpour, A; Das, N K

    2013-02-28

    We have proposed an all-optical AND logic gate based on four-wave mixing (FWM) in a semiconductor optical amplifier (SOA) integrated with an optical filter. In the scheme proposed, the preferred logical function can be performed without using a continuous-wave (cw) signal. The modified nonlinear Schroedinger equation (MNLSE) is used for the modelling wave propagation in a SOA. The MNLSE takes into account all nonlinear effects relevant to pico- and sub-picosecond pulse durations and is solved by the finite-difference beam-propagation method (FD-BPM). Based on the simulation results, the optimal output signal with a 40-fJ energy can be obtained at a bit rate of 50 Gb s{sup -1}. In the simulations, besides the nonlinearities included in the model, the pattern effect of the signals propagating in the SOA medium and the effect of the input signal bit rate are extensively investigated to optimise the system performance. (optical logic elements)

  1. SEMICONDUCTOR DEVICES: Small-signal model parameter extraction for microwave SiGe HBTs based on Y- and Z-parameter characterization

    NASA Astrophysics Data System (ADS)

    Jun, Fu

    2009-08-01

    High frequency intrinsic small-signal model parameter extraction for microwave SiGe heterojunction bipolar transistors is studied, with a focus on the main feedback elements including the emitter series resistor, internal and external base-collector capacitors as well as the base series resistor, all of which are important in determining the behavior of the device equivalent circuit. In accordance with the respective features of definition of the Y- and Z-parameters, a novel combined use of them succeeds in reasonably simplifying the device equivalent circuit and thus decoupling the extraction of base-collector capacitances from other model parameters. As a result, a very simple direct extraction method is proposed. The proposed method is applied for determining the SiGe HBT small-signal model parameters by taking numerically simulated Y- and Z-parameters as nominal “measurement data" with the help of a Taurus-device simulator. The validity of the method is preliminarily confirmed by the observation of certain linear relations of device frequency behavior as predicted by the corresponding theoretical analysis. Furthermore, the extraction results can be used to reasonably account for the dependence of the extracted model parameters on device geometry and process parameters, reflecting the explicit physical meanings of parameters, and especially revealing the distributed nature of the base series resistor and its complex interactions with base-collector capacitors. Finally, the accuracy of our model parameter extraction method is further validated by comparing the modeled and simulated S-parameters as a function of frequency.

  2. All Optical Solution for Free Space Optics Point to Point Links

    NASA Astrophysics Data System (ADS)

    Hirayama, Daigo

    Optical network systems are quickly replacing electrical network systems. Optical systems provide better bandwidth, faster data rates, better security to networks, and are less susceptible to noise. Free Space Optics (systems) still rely on numerous electrical systems such as the modulation and demodulation systems to convert optical signals to electrical signals for the transmitting laser. As the concept of the entirely optical network becomes more realizable, the electrical components of the FSO system will become a hindrance to communications. The focus of this thesis is to eliminate the electrical devices for the FSO point to point links by replacing them with optical devices. The concept is similar to an extended beam connector. However, where an extended beam connector deals with a gap of a few millimeters, my focus looks at distances from 100 meters to one kilometer. The aim is to achieve a detectable signal of 1nW at a distance of 500 meters at a wavelength of 1500-1600nm. This leads to application in building to building links and mobile networks. The research examines the design of the system in terms of generating the wave, the properties of the fiber feeding the wave, and the power necessary to achieve a usable distance. The simulation is executed in Code V by Synopsys, which is an industry standard to analyze optical systems. A usable device with a range of around 500m was achieved with an input power of 1mW. The approximations of the phase function resulted in some aberrations to the profile of the beam, but were not very detrimental to the function of the device. The removal of electrical devices from a FSO point to point link decreased the power used to establish the link and decreased the cost.

  3. Portable microwave instrument for non-destructive evaluation of structural characteristics

    DOEpatents

    Bible, Don W.; Crutcher, Richard I.; Sohns, Carl W.; Maddox, Stephen R.

    1995-01-01

    A portable microwave instrument for evaluating characteristics of a structural member includes a source of microwave energy, a transmitter coupled to the source of microwave energy for transmitting a microwave signal at the structural member, and a receiver positioned on the same side of the structural member as the transmitter and being disposed to receive a microwave signal reflected by the structural member. A phase angle difference is determined between the transmitted microwave signal and the received microwave signal using a signal splitter and a balanced mixer. The difference in phase angle varies in accordance with differences in size, shape and locations of constituent materials within the structural member.

  4. Portable microwave instrument for non-destructive evaluation of structural characteristics

    DOEpatents

    Bible, D.W.; Crutcher, R.I.; Sohns, C.W.; Maddox, S.R.

    1995-01-24

    A portable microwave instrument for evaluating characteristics of a structural member includes a source of microwave energy, a transmitter coupled to the source of microwave energy for transmitting a microwave signal at the structural member, and a receiver positioned on the same side of the structural member as the transmitter and being disposed to receive a microwave signal reflected by the structural member. A phase angle difference is determined between the transmitted microwave signal and the received microwave signal using a signal splitter and a balanced mixer. The difference in phase angle varies in accordance with differences in size, shape and locations of constituent materials within the structural member. 6 figures.

  5. On the suitability of fibre optical parametric amplifiers for use in all-optical agile photonic networks

    NASA Astrophysics Data System (ADS)

    Gryspolakis, Nikolaos

    B. Next, we introduce modulated channels to the amplifier in order to compare their effect on the Bit Error Rate (BER) performance. We consider the impact on FOPAs when employing different modulation formats, such as RZ, NRZ and RZ-DPSK. Carefully selected modulation formats can improve BER performance and reduce the effects of cross-phase modulation, four wave mixing (FWM) products generation or dispersion (non-linear and linear inter-channel interference). Especially for the case of FOPAs, because of the ultra-fast interaction times of the FWM phenomenon, cross gain modulation can be a great deterrent for using FOPAs. We use RZ-DPSK in order to suppress the WDM signal crosstalk. Only by using RZ-DPSK, we obtain an improved receiver sensitivity of 5 dB when operating at 40 Gb/s. Finally, we investigate ways to mitigate such effects as the ones described above (gain excursions, gain tilt, etc.). We demonstrate that by using a ring configuration with optical feedback for the first time in FOPAs, we can achieve all-optical gain clamping (AOGC), mitigating gain excursions and attaining gain, independent of channel input power for a large range of PCIP. For example, with the use of AOGC, we reduce the add/drop-induced gain excursions from 4 dB to 0.6 dB. Also, by the combined use of AOGC and RZ-DPSK, we mitigate most of the aforementioned hindrances described above.

  6. All-optical digital logic: Full addition or subtraction on a three-state system

    SciTech Connect

    Remacle, F.; Levine, R. D.

    2006-03-15

    Stimulated Raman adiabatic passage (STIRAP) is a well-studied pump-probe control scheme for manipulating the population of quantum states of atoms or molecules. By encoding the digits to be operated on as 'on' or 'off' laser input signals we show how STIRAP can be used to implement a finite-state logic machine. The physical conditions required for an effective STIRAP operation are related to the physical conditions expected for a logic machine. In particular, a condition is derived on the mean number of photons that represent an on pulse. A finite-state machine computes Boolean expressions that depend both on the input and on the present state of the machine. With two input signals we show how to implement a full adder where the carry-in digit is stored in the state of the machine. Furthermore, we show that it is possible to store the carry-out digit as the next state and thereby return the machine to a state ready for the next full addition. Such a machine operates as a cyclical full adder. We further show how this full adder can equally well be operated as a full subtractor. To the best of our knowledge this is the first example of a nanosized system that implements a full subtraction.

  7. All-optical video-image encryption with enforced security level using independent component analysis

    NASA Astrophysics Data System (ADS)

    Alfalou, A.; Mansour, A.

    2007-10-01

    In the last two decades, wireless communications have been introduced in various applications. However, the transmitted data can be, at any moment, intercepted by non-authorized people. That could explain why data encryption and secure transmission have gained enormous popularity. In order to secure data transmission, we should pay attention to two aspects: transmission rate and encryption security level. In this paper, we address these two aspects by proposing a new video-image transmission scheme. This new system consists in using the advantage of optical high transmission rate and some powerful signal processing tools to secure the transmitted data. The main idea of our approach is to secure transmitted information at two levels: at the classical level by using an adaptation of standard optical techniques and at a second level (spatial diversity) by using independent transmitters. In the second level, a hacker would need to intercept not only one channel but all of them in order to retrieve information. At the receiver, we can easily apply ICA algorithms to decrypt the received signals and retrieve information.

  8. Measurement Sensitivity Improvement of All-Optical Atomic Spin Magnetometer by Suppressing Noises.

    PubMed

    Chen, Xiyuan; Zhang, Hong; Zou, Sheng

    2016-06-17

    Quantum manipulation technology and photoelectric detection technology have jointly facilitated the rapid development of ultra-sensitive atomic spin magnetometers. To improve the output signal and sensitivity of the spin-exchange-relaxation-free (SERF) atomic spin magnetometer, the noises influencing on the output signal and the sensitivity were analyzed, and the corresponding noise suppression methods were presented. The magnetic field noises, including the residual magnetic field noise and the light shift noise, were reduced to approximately zero by employing the magnetic field compensation method and by adjusting the frequency of the pump beam, respectively. With respect to the operation temperature, the simulation results showed that the temperature of the potassium atomic spin magnetometer realizing the spin-exchange relaxation-free regime was 180 °C. Moreover, the fluctuation noises of the frequency and the power were suppressed by using the frequency and the power stable systems. The experimental power stability results showed that the light intensity stability was enhanced 10%. Contrast experiments on the sensitivity were carried out to demonstrate the validity of the suppression methods. Finally, a sensitivity of 13 fT/Hz(1/2) was successfully achieved by suppressing noises and optimizing parameters.

  9. Measurement Sensitivity Improvement of All-Optical Atomic Spin Magnetometer by Suppressing Noises

    PubMed Central

    Chen, Xiyuan; Zhang, Hong; Zou, Sheng

    2016-01-01

    Quantum manipulation technology and photoelectric detection technology have jointly facilitated the rapid development of ultra-sensitive atomic spin magnetometers. To improve the output signal and sensitivity of the spin-exchange-relaxation-free (SERF) atomic spin magnetometer, the noises influencing on the output signal and the sensitivity were analyzed, and the corresponding noise suppression methods were presented. The magnetic field noises, including the residual magnetic field noise and the light shift noise, were reduced to approximately zero by employing the magnetic field compensation method and by adjusting the frequency of the pump beam, respectively. With respect to the operation temperature, the simulation results showed that the temperature of the potassium atomic spin magnetometer realizing the spin-exchange relaxation-free regime was 180 °C. Moreover, the fluctuation noises of the frequency and the power were suppressed by using the frequency and the power stable systems. The experimental power stability results showed that the light intensity stability was enhanced 10%. Contrast experiments on the sensitivity were carried out to demonstrate the validity of the suppression methods. Finally, a sensitivity of 13 fT/Hz1/2 was successfully achieved by suppressing noises and optimizing parameters. PMID:27322272

  10. Microwave detector

    DOEpatents

    Meldner, H.W.; Cusson, R.Y.; Johnson, R.M.

    1985-02-08

    A microwave detector is provided for measuring the envelope shape of a microwave pulse comprised of high-frequency oscillations. A biased ferrite produces a magnetization field flux that links a B-dot loop. The magnetic field of the microwave pulse participates in the formation of the magnetization field flux. High-frequency insensitive means are provided for measuring electric voltage or current induced in the B-dot loop. The recorded output of the detector is proportional to the time derivative of the square of the envelope shape of the microwave pulse.

  11. Microwave detector

    DOEpatents

    Meldner, Heiner W.; Cusson, Ronald Y.; Johnson, Ray M.

    1986-01-01

    A microwave detector (10) is provided for measuring the envelope shape of a microwave pulse comprised of high-frequency oscillations. A biased ferrite (26, 28) produces a magnetization field flux that links a B-dot loop (16, 20). The magnetic field of the microwave pulse participates in the formation of the magnetization field flux. High-frequency insensitive means (18, 22) are provided for measuring electric voltage or current induced in the B-dot loop. The recorded output of the detector is proportional to the time derivative of the square of the envelope shape of the microwave pulse.

  12. Polarization self-selection in a coherent beam combination system with an all-optical feedback loop.

    PubMed

    Liu, Houkang; He, Bing; Zhou, Jun; Liu, Chi; Dong, Jingxing; Wei, Yunrong; Lou, Qihong

    2012-09-20

    Polarization self-selection in passive phasing of four fiber amplifiers with an all-optical feedback loop is demonstrated. The polarization extinction ratio (PER) of the combined beam is increased, and the polarized direction is selected with the use of a polarization-maintaining (PM) isolator and some non-PM components. The best visibility of the interference patterns is observed at 95.2% and in the largest increment in the PER of the combined beam up to 7.4 dB. Results show that all PM components are unnecessary in the coherent beam combination with an all-optical feedback loop, whereas non-PM components have good potential to achieve high output power.

  13. All-optical investigation of tunable picosecond magnetization dynamics in ferromagnetic nanostripes with a width down to 50 nm.

    PubMed

    Saha, Susmita; Barman, Saswati; Otani, YoshiChika; Barman, Anjan

    2015-11-21

    Ferromagnetic nanostripes are important elements for a number of interesting technologies including magnetic racetrack memory, spin logic and magnonics. Understanding and controlling magnetization dynamics in such nanostripes are hence important problems in nanoscience and technology. Here we present an all-optical excitation and detection of ultrafast magnetization dynamics, including spin waves, in 5 μm long Ni80Fe20 nanostripes with varying stripe widths from 200 nm down to 50 nm. We observed a strong width dependent variation in the frequency, anisotropy and the spatial nature of spin waves in these systems. The effect of inter-stripe interaction is also studied and the 50 nm wide stripe is found to be nearly magnetostatically isolated, allowing us to detect the dynamics of a 50 nm wide individual stripe using an all-optical measurement technique. The tunability in magnetization dynamics with stripe widths is important for their applications in various spin based technologies.

  14. All-optical ultrafast XOR/XNOR logic gates, binary counter, and double-bit comparator with silicon microring resonators.

    PubMed

    Sethi, Purnima; Roy, Sukhdev

    2014-10-01

    We present designs of all-optical ultrafast YES/NOT, XOR/XNOR logic gates, binary counter, and double-bit comparator based on all-optical switching by two-photon absorption induced free-carrier injection in silicon 2 × 2 add-drop microring resonators. The proposed circuits have been theoretically analyzed using time-domain coupled-mode theory based on reported experimental values to realize low power (∼ 28 mW) ultrafast (∼ 22 ps) operation with high modulation (80%) and bit rate (45 Gb/s). The designs are complementary metal-oxide semiconductor compatible and provide advantages of high Q-factor, tunability, compactness, cascadibility, scalability, reconfigurability, simplicity, and minimal number of switches and inputs for realization of the desired logic. Although a two-bit counter has been shown, the scheme can easily be extended to N-bit counter through cascading.

  15. Sub-wavelength terahertz beam profiling of a THz source via an all-optical knife-edge technique.

    PubMed

    Phing, Sze Ho; Mazhorova, Anna; Shalaby, Mostafa; Peccianti, Marco; Clerici, Matteo; Pasquazi, Alessia; Ozturk, Yavuz; Ali, Jalil; Morandotti, Roberto

    2015-02-25

    Terahertz technologies recently emerged as outstanding candidates for a variety of applications in such sectors as security, biomedical, pharmaceutical, aero spatial, etc. Imaging the terahertz field, however, still remains a challenge, particularly when sub-wavelength resolutions are involved. Here we demonstrate an all-optical technique for the terahertz near-field imaging directly at the source plane. A thin layer (<100 nm-thickness) of photo carriers is induced on the surface of the terahertz generation crystal, which acts as an all-optical, virtual blade for terahertz near-field imaging via a knife-edge technique. Remarkably, and in spite of the fact that the proposed approach does not require any mechanical probe, such as tips or apertures, we are able to demonstrate the imaging of a terahertz source with deeply sub-wavelength features (<30 μm) directly in its emission plane.

  16. Optical FFT/IFFT circuit realization using arrayed waveguide gratings and the applications in all-optical OFDM system.

    PubMed

    Wang, Zhenxing; Kravtsov, Konstantin S; Huang, Yue-Kai; Prucnal, Paul R

    2011-02-28

    Arrayed waveguide gratings (AWG) are widely used as wavelength division multiplexers (MUX) and demultiplexers (DEMUX) in optical networks. Here we propose and demonstrate that conventional AWGs can also be used as integrated spectral filters to realize a Fast Fourier transform (FFT) and its inverse form (IFFT). More specifically, we point out that the wavelength selection conditions of AWGs when used as wavelength MUX/DEMUX also enable them to perform FFT/IFFT functions. Therefore, previous research on AWGs can now be applied to optical FFT/IFFT circuit design. Compared with other FFT/IFFT optical circuits, AWGs have less structural complexity, especially for a large number of inputs and outputs. As an important application, AWGs can be used in optical OFDM systems. We propose an all-optical OFDM system with AWGs and demonstrate the simulation results. Overall, the AWG provides a feasible solution for all-optical OFDM systems, especially with a large number of optical subcarriers.

  17. All-optical investigation of tunable picosecond magnetization dynamics in ferromagnetic nanostripes with a width down to 50 nm

    NASA Astrophysics Data System (ADS)

    Saha, Susmita; Barman, Saswati; Otani, Yoshichika; Barman, Anjan

    2015-10-01

    Ferromagnetic nanostripes are important elements for a number of interesting technologies including magnetic racetrack memory, spin logic and magnonics. Understanding and controlling magnetization dynamics in such nanostripes are hence important problems in nanoscience and technology. Here we present an all-optical excitation and detection of ultrafast magnetization dynamics, including spin waves, in 5 μm long Ni80Fe20 nanostripes with varying stripe widths from 200 nm down to 50 nm. We observed a strong width dependent variation in the frequency, anisotropy and the spatial nature of spin waves in these systems. The effect of inter-stripe interaction is also studied and the 50 nm wide stripe is found to be nearly magnetostatically isolated, allowing us to detect the dynamics of a 50 nm wide individual stripe using an all-optical measurement technique. The tunability in magnetization dynamics with stripe widths is important for their applications in various spin based technologies.

  18. Advanced components for microwave photonics

    NASA Astrophysics Data System (ADS)

    Fonjallaz, Pierre-Yves; Gunnarsson, Ola; Popov, Mikhail; Margulis, Walter; Petermann, Ingemar; Berlemont, David; Carlsson, Fredrik

    2003-04-01

    This persentation gives an overveiw of the field of microwave photonics with an emphasis on new fiber based devices which we belive have a real practical potential. Microwave photonics can be considered as the fruitful meeting point bewteen optics and microwave engineering, where optoelectronic devices and systems are used both for processing at microwave rates and for signal handling in microwave systems. The use of specialty fibers, glass poling and naturally fiber Bragg gratings opens new perspectives for the realization of low-cost devices with appropriate functionality. The application field for optical microwave transmission and processing spans from radar technology to cable TV and mobile communications systems. Over the last few years very much attention has been directed towards radio-over-fiber systems for the next-generation mobile communications infrastructure as well as hybrid fiber radio for picocell systems at 60 GHz or above. As a matter of fact, the higher the microwave frequencies, the greater are the similarities with the optical carrier and the more there is to be gained by processing the microwave signal in the optical domain. Other important application examples are beamforming networks for phased array antennas and subcarrier processing for routing in optical networks.

  19. On the size-dependent magnetism and all-optical magnetization switching of transition-metal silicide nanostructures

    SciTech Connect

    Glushkov, G. I.; Tuchin, A. V.; Popov, S. V.; Bityutskaya, L. A.

    2015-12-15

    Theoretical investigations of the electronic structure, synthesis, and all-optical magnetization switching of transition-metal silicide nanostructures are reported. The magnetic moment of the nanostructures is studied as a function of the silicide cluster size and configuration. The experimentally demonstrated magnetization switching of nanostructured nickel silicide by circularly polarized light makes it possible to create high-speed storage devices with high density data recording.

  20. All-optical modulator cells based on AlGaAs/GaAs/InGaAs 905-nm laser heterostructures

    NASA Astrophysics Data System (ADS)

    Podoskin, A. A.; Shashkin, I. S.; Slipchenko, S. O.; Pikhtin, N. A.; Tarasov, I. S.

    2017-01-01

    All-optical cells based on AlGaAs/GaAs/InGaAs laser heterostructures for a 905-nm wavelength have been developed, which operate in the regime of optical-power modulation by means of controlled generation switching between the Fabry-Perot cavity modes and high-Q closed mode. At a modulated power of 1.6 W, a mode-switching time of 1.2 ns and smaller is achieved.